OpenJDK 1.23 · java.util.stream.IntStream · APIdia, the JavaDoc alternative

Modifier and Type	Class and Description
public static interface	IntStream.Builder A mutable builder for an `IntStream`.
public static interface	IntStream.IntMapMultiConsumer Represents an operation that accepts an `int`-valued argument and an IntConsumer, and returns no result.

Method Summary

Modifier and Type	Method and Description
public boolean	Returns: `true` if either all elements of the stream match the provided predicate or the stream is empty, otherwise `false` allMatch(IntPredicate a non-interfering, stateless predicate to apply to elements of this stream predicate) Returns whether all elements of this stream match the provided predicate.
public boolean	Returns: `true` if any elements of the stream match the provided predicate, otherwise `false` anyMatch(IntPredicate a non-interfering, stateless predicate to apply to elements of this stream predicate) Returns whether any elements of this stream match the provided predicate.
public DoubleStream	Returns: a `DoubleStream` consisting of the elements of this stream, converted to `double` asDoubleStream() Returns a `DoubleStream` consisting of the elements of this stream, converted to `double`.
public LongStream	Returns: a `LongStream` consisting of the elements of this stream, converted to `long` asLongStream() Returns a `LongStream` consisting of the elements of this stream, converted to `long`.
public OptionalDouble	Returns: an `OptionalDouble` containing the average element of this stream, or an empty optional if the stream is empty average() Returns an `OptionalDouble` describing the arithmetic mean of elements of this stream, or an empty optional if this stream is empty.
public Stream<Integer>	Returns: a `Stream` consistent of the elements of this stream, each boxed to an `Integer` boxed() Returns a `Stream` consisting of the elements of this stream, each boxed to an `Integer`.
public static IntStream.Builder	Returns: a stream builder builder() Returns a builder for an `IntStream`.
public < the type of the mutable result container R> R	Returns: the result of the reduction collect(Supplier<R> a function that creates a new mutable result container. For a parallel execution, this function may be called multiple times and must return a fresh value each time. supplier, ObjIntConsumer<R> an associative, non-interfering, stateless function that must fold an element into a result container. accumulator, BiConsumer<R, R> an associative, non-interfering, stateless function that accepts two partial result containers and merges them, which must be compatible with the accumulator function. The combiner function must fold the elements from the second result container into the first result container. combiner) Performs a mutable reduction operation on the elements of this stream.
public static IntStream	Returns: the concatenation of the two input streams concat(IntStream the first stream a, IntStream the second stream b) Creates a lazily concatenated stream whose elements are all the elements of the first stream followed by all the elements of the second stream.
public long	Returns: the count of elements in this stream count() Returns the count of elements in this stream.
public IntStream	Returns: the new stream distinct() Returns a stream consisting of the distinct elements of this stream.
public default IntStream	Returns: the new stream dropWhile(IntPredicate a non-interfering, stateless predicate to apply to elements to determine the longest prefix of elements. predicate) Returns, if this stream is ordered, a stream consisting of the remaining elements of this stream after dropping the longest prefix of elements that match the given predicate.
public static IntStream	Returns: an empty sequential stream empty() Returns an empty sequential `IntStream`.
public IntStream	Returns: the new stream filter(IntPredicate a non-interfering, stateless predicate to apply to each element to determine if it should be included predicate) Returns a stream consisting of the elements of this stream that match the given predicate.
public OptionalInt	Returns: an `OptionalInt` describing some element of this stream, or an empty `OptionalInt` if the stream is empty findAny() Returns an `OptionalInt` describing some element of the stream, or an empty `OptionalInt` if the stream is empty.
public OptionalInt	Returns: an `OptionalInt` describing the first element of this stream, or an empty `OptionalInt` if the stream is empty findFirst() Returns an `OptionalInt` describing the first element of this stream, or an empty `OptionalInt` if the stream is empty.
public IntStream	Returns: the new stream flatMap(IntFunction<? extends IntStream> a non-interfering, stateless function to apply to each element which produces an `IntStream` of new values mapper) Returns a stream consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element.
public void	forEach(IntConsumer a non-interfering action to perform on the elements action) Performs an action for each element of this stream.
public void	forEachOrdered(IntConsumer a non-interfering action to perform on the elements action) Performs an action for each element of this stream, guaranteeing that each element is processed in encounter order for streams that have a defined encounter order.
public static IntStream	Returns: a new infinite sequential unordered `IntStream` generate(IntSupplier the `IntSupplier` for generated elements s) Returns an infinite sequential unordered stream where each element is generated by the provided `IntSupplier`.
public static IntStream	Returns: a new sequential `IntStream` iterate(final int the initial element seed, final IntUnaryOperator a function to be applied to the previous element to produce a new element f) Returns an infinite sequential ordered `IntStream` produced by iterative application of a function `f` to an initial element `seed`, producing a `Stream` consisting of `seed`, `f(seed)`, `f(f(seed))`, etc. The first element (position `0`) in the `IntStream` will be the provided `seed`.
public static IntStream	Returns: a new sequential `IntStream` iterate(int the initial element seed, IntPredicate a predicate to apply to elements to determine when the stream must terminate. hasNext, IntUnaryOperator a function to be applied to the previous element to produce a new element next) Returns a sequential ordered `IntStream` produced by iterative application of the given `next` function to an initial element, conditioned on satisfying the given `hasNext` predicate.
public PrimitiveIterator.OfInt	iterator() Redeclares java.util.stream.BaseStream.iterator. Returns an iterator for the elements of this stream.
public IntStream	Returns: the new stream limit(long the number of elements the stream should be limited to maxSize) Returns a stream consisting of the elements of this stream, truncated to be no longer than `maxSize` in length.
public IntStream	Returns: the new stream map(IntUnaryOperator a non-interfering, stateless function to apply to each element mapper) Returns a stream consisting of the results of applying the given function to the elements of this stream.
public default IntStream	Returns: the new stream mapMulti(IntStream.IntMapMultiConsumer a non-interfering, stateless function that generates replacement elements mapper) Returns a stream consisting of the results of replacing each element of this stream with multiple elements, specifically zero or more elements.
public DoubleStream	Returns: the new stream mapToDouble(IntToDoubleFunction a non-interfering, stateless function to apply to each element mapper) Returns a `DoubleStream` consisting of the results of applying the given function to the elements of this stream.
public LongStream	Returns: the new stream mapToLong(IntToLongFunction a non-interfering, stateless function to apply to each element mapper) Returns a `LongStream` consisting of the results of applying the given function to the elements of this stream.
public < the element type of the new stream U> Stream<U>	Returns: the new stream mapToObj(IntFunction<? extends U> a non-interfering, stateless function to apply to each element mapper) Returns an object-valued `Stream` consisting of the results of applying the given function to the elements of this stream.
public OptionalInt	Returns: an `OptionalInt` containing the maximum element of this stream, or an empty `OptionalInt` if the stream is empty max() Returns an `OptionalInt` describing the maximum element of this stream, or an empty optional if this stream is empty.
public OptionalInt	Returns: an `OptionalInt` containing the minimum element of this stream, or an empty `OptionalInt` if the stream is empty min() Returns an `OptionalInt` describing the minimum element of this stream, or an empty optional if this stream is empty.
public boolean	Returns: `true` if either no elements of the stream match the provided predicate or the stream is empty, otherwise `false` noneMatch(IntPredicate a non-interfering, stateless predicate to apply to elements of this stream predicate) Returns whether no elements of this stream match the provided predicate.
public static IntStream	Returns: a singleton sequential stream of(int the single element t) Returns a sequential `IntStream` containing a single element.
public static IntStream	Returns: the new stream of(int... the elements of the new stream values) Returns a sequential ordered stream whose elements are the specified values.
public IntStream	parallel() Redeclares java.util.stream.BaseStream.parallel. Returns an equivalent stream that is parallel.
public IntStream	Returns: the new stream peek(IntConsumer a non-interfering action to perform on the elements as they are consumed from the stream action) Returns a stream consisting of the elements of this stream, additionally performing the provided action on each element as elements are consumed from the resulting stream.
public static IntStream	Returns: a sequential `IntStream` for the range of `int` elements range(int the (inclusive) initial value startInclusive, int the exclusive upper bound endExclusive) Returns a sequential ordered `IntStream` from `startInclusive` (inclusive) to `endExclusive` (exclusive) by an incremental step of `1`.
public static IntStream	Returns: a sequential `IntStream` for the range of `int` elements rangeClosed(int the (inclusive) initial value startInclusive, int the inclusive upper bound endInclusive) Returns a sequential ordered `IntStream` from `startInclusive` (inclusive) to `endInclusive` (inclusive) by an incremental step of `1`.
public int	Returns: the result of the reduction reduce(int the identity value for the accumulating function identity, IntBinaryOperator an associative, non-interfering, stateless function for combining two values op) Performs a reduction on the elements of this stream, using the provided identity value and an associative accumulation function, and returns the reduced value.
public OptionalInt	Returns: the result of the reduction reduce(IntBinaryOperator an associative, non-interfering, stateless function for combining two values op) Performs a reduction on the elements of this stream, using an associative accumulation function, and returns an `OptionalInt` describing the reduced value, if any.
public IntStream	sequential() Redeclares java.util.stream.BaseStream.sequential. Returns an equivalent stream that is sequential.
public IntStream	Returns: the new stream skip(long the number of leading elements to skip n) Returns a stream consisting of the remaining elements of this stream after discarding the first `n` elements of the stream.
public IntStream	Returns: the new stream sorted() Returns a stream consisting of the elements of this stream in sorted order.
public Spliterator.OfInt	spliterator() Redeclares java.util.stream.BaseStream.spliterator. Returns a spliterator for the elements of this stream.
public int	Returns: the sum of elements in this stream sum() Returns the sum of elements in this stream.
public IntSummaryStatistics	Returns: an `IntSummaryStatistics` describing various summary data about the elements of this stream summaryStatistics() Returns an `IntSummaryStatistics` describing various summary data about the elements of this stream.
public default IntStream	Returns: the new stream takeWhile(IntPredicate a non-interfering, stateless predicate to apply to elements to determine the longest prefix of elements. predicate) Returns, if this stream is ordered, a stream consisting of the longest prefix of elements taken from this stream that match the given predicate.
public int[]	Returns: an array containing the elements of this stream toArray() Returns an array containing the elements of this stream.

Inherited from java.util.stream.BaseStream:: close isParallel onClose unordered

Method Detail

allMatch back to summary

allMatch	back to summary
public boolean allMatch(IntPredicate predicate) Returns whether all elements of this stream match the provided predicate. May not evaluate the predicate on all elements if not necessary for determining the result. If the stream is empty then `true` is returned and the predicate is not evaluated. This is a short-circuiting terminal operation. API Note This method evaluates the universal quantification of the predicate over the elements of the stream (for all x P(x)). If the stream is empty, the quantification is said to be vacuously satisfied and is always `true` (regardless of P(x)). Parameters predicate:IntPredicate a non-interfering, stateless predicate to apply to elements of this stream Returns:boolean `true` if either all elements of the stream match the provided predicate or the stream is empty, otherwise `false`

public boolean allMatch(IntPredicate predicate)

Returns whether all elements of this stream match the provided predicate. May not evaluate the predicate on all elements if not necessary for determining the result. If the stream is empty then true is returned and the predicate is not evaluated.

This is a short-circuiting terminal operation.

API Note

This method evaluates the universal quantification of the predicate over the elements of the stream (for all x P(x)). If the stream is empty, the quantification is said to be vacuously satisfied and is always true (regardless of P(x)).

Parameters

predicate:IntPredicate: a non-interfering, stateless predicate to apply to elements of this stream

Returns:boolean

true if either all elements of the stream match the provided predicate or the stream is empty, otherwise false

anyMatch back to summary

anyMatch	back to summary
public boolean anyMatch(IntPredicate predicate) Returns whether any elements of this stream match the provided predicate. May not evaluate the predicate on all elements if not necessary for determining the result. If the stream is empty then `false` is returned and the predicate is not evaluated. This is a short-circuiting terminal operation. API Note This method evaluates the existential quantification of the predicate over the elements of the stream (for some x P(x)). Parameters predicate:IntPredicate a non-interfering, stateless predicate to apply to elements of this stream Returns:boolean `true` if any elements of the stream match the provided predicate, otherwise `false`

public boolean anyMatch(IntPredicate predicate)

Returns whether any elements of this stream match the provided predicate. May not evaluate the predicate on all elements if not necessary for determining the result. If the stream is empty then false is returned and the predicate is not evaluated.

This is a short-circuiting terminal operation.

API Note

This method evaluates the existential quantification of the predicate over the elements of the stream (for some x P(x)).

Parameters

predicate:IntPredicate: a non-interfering, stateless predicate to apply to elements of this stream

Returns:boolean

true if any elements of the stream match the provided predicate, otherwise false

asDoubleStream back to summary

asDoubleStream	back to summary
public DoubleStream asDoubleStream() Returns a `DoubleStream` consisting of the elements of this stream, converted to `double`. This is an intermediate operation. Returns:DoubleStream a `DoubleStream` consisting of the elements of this stream, converted to `double`

public DoubleStream asDoubleStream()

Returns a DoubleStream consisting of the elements of this stream, converted to double.

This is an intermediate operation.

Returns:DoubleStream: a DoubleStream consisting of the elements of this stream, converted to double

asLongStream back to summary

asLongStream	back to summary
public LongStream asLongStream() Returns a `LongStream` consisting of the elements of this stream, converted to `long`. This is an intermediate operation. Returns:LongStream a `LongStream` consisting of the elements of this stream, converted to `long`

public LongStream asLongStream()

Returns a LongStream consisting of the elements of this stream, converted to long.

This is an intermediate operation.

Returns:LongStream: a LongStream consisting of the elements of this stream, converted to long

average back to summary

average	back to summary
public OptionalDouble average() Returns an `OptionalDouble` describing the arithmetic mean of elements of this stream, or an empty optional if this stream is empty. This is a special case of a reduction. This is a terminal operation. Returns:OptionalDouble an `OptionalDouble` containing the average element of this stream, or an empty optional if the stream is empty

public OptionalDouble average()

Returns an OptionalDouble describing the arithmetic mean of elements of this stream, or an empty optional if this stream is empty. This is a special case of a reduction.

This is a terminal operation.

Returns:OptionalDouble: an OptionalDouble containing the average element of this stream, or an empty optional if the stream is empty

boxed back to summary

boxed	back to summary
public Stream<Integer> boxed() Returns a `Stream` consisting of the elements of this stream, each boxed to an `Integer`. This is an intermediate operation. Returns:Stream<Integer> a `Stream` consistent of the elements of this stream, each boxed to an `Integer`

public Stream<Integer> boxed()

Returns a Stream consisting of the elements of this stream, each boxed to an Integer.

This is an intermediate operation.

Returns:Stream<Integer>: a Stream consistent of the elements of this stream, each boxed to an Integer

builder back to summary

builder	back to summary
public static IntStream.Builder builder() Returns a builder for an `IntStream`. Returns:IntStream.Builder a stream builder

public static IntStream.Builder builder()

Returns a builder for an IntStream.

Returns:IntStream.Builder: a stream builder

collect back to summary

collect	back to summary
public <R> R collect(Supplier<R> supplier, ObjIntConsumer<R> accumulator, BiConsumer<R, R> combiner) Performs a mutable reduction operation on the elements of this stream. A mutable reduction is one in which the reduced value is a mutable result container, such as an `ArrayList`, and elements are incorporated by updating the state of the result rather than by replacing the result. This produces a result equivalent to: `R result = supplier.get(); for (int element : this stream) accumulator.accept(result, element); return result;` Like `reduce(int, IntBinaryOperator)`, `collect` operations can be parallelized without requiring additional synchronization. This is a terminal operation. Parameters <R> the type of the mutable result container supplier:Supplier<R> a function that creates a new mutable result container. For a parallel execution, this function may be called multiple times and must return a fresh value each time. accumulator:ObjIntConsumer<R> an associative, non-interfering, stateless function that must fold an element into a result container. combiner:BiConsumer<R, R> an associative, non-interfering, stateless function that accepts two partial result containers and merges them, which must be compatible with the accumulator function. The combiner function must fold the elements from the second result container into the first result container. Returns:R the result of the reduction See Also `Stream#collect(Supplier, BiConsumer, BiConsumer)`

public <R> R collect(Supplier<R> supplier, ObjIntConsumer<R> accumulator, BiConsumer<R, R> combiner)

Performs a mutable reduction operation on the elements of this stream. A mutable reduction is one in which the reduced value is a mutable result container, such as an ArrayList, and elements are incorporated by updating the state of the result rather than by replacing the result. This produces a result equivalent to:

R result = supplier.get();
    for (int element : this stream)
        accumulator.accept(result, element);
    return result;

Like reduce(int, IntBinaryOperator), collect operations can be parallelized without requiring additional synchronization.

This is a terminal operation.

Parameters

<R>: the type of the mutable result container
supplier:Supplier<R>: a function that creates a new mutable result container. For a parallel execution, this function may be called multiple times and must return a fresh value each time.
accumulator:ObjIntConsumer<R>: an associative, non-interfering, stateless function that must fold an element into a result container.
combiner:BiConsumer<R, R>: an associative, non-interfering, stateless function that accepts two partial result containers and merges them, which must be compatible with the accumulator function. The combiner function must fold the elements from the second result container into the first result container.

Returns:R

the result of the reduction

concat back to summary

concat	back to summary
public static IntStream concat(IntStream a, IntStream b) Creates a lazily concatenated stream whose elements are all the elements of the first stream followed by all the elements of the second stream. The resulting stream is ordered if both of the input streams are ordered, and parallel if either of the input streams is parallel. When the resulting stream is closed, the close handlers for both input streams are invoked. This method operates on the two input streams and binds each stream to its source. As a result subsequent modifications to an input stream source may not be reflected in the concatenated stream result. Implementation Note Use caution when constructing streams from repeated concatenation. Accessing an element of a deeply concatenated stream can result in deep call chains, or even `StackOverflowError`. API Note To preserve optimization opportunities this method binds each stream to its source and accepts only two streams as parameters. For example, the exact size of the concatenated stream source can be computed if the exact size of each input stream source is known. To concatenate more streams without binding, or without nested calls to this method, try creating a stream of streams and flat-mapping with the identity function, for example: `IntStream concat = Stream.of(s1, s2, s3, s4).flatMapToInt(s -> s);` Parameters a:IntStream the first stream b:IntStream the second stream Returns:IntStream the concatenation of the two input streams

public static IntStream concat(IntStream a, IntStream b)

Creates a lazily concatenated stream whose elements are all the elements of the first stream followed by all the elements of the second stream. The resulting stream is ordered if both of the input streams are ordered, and parallel if either of the input streams is parallel. When the resulting stream is closed, the close handlers for both input streams are invoked.

This method operates on the two input streams and binds each stream to its source. As a result subsequent modifications to an input stream source may not be reflected in the concatenated stream result.

Implementation Note

Use caution when constructing streams from repeated concatenation. Accessing an element of a deeply concatenated stream can result in deep call chains, or even StackOverflowError.

API Note

To preserve optimization opportunities this method binds each stream to its source and accepts only two streams as parameters. For example, the exact size of the concatenated stream source can be computed if the exact size of each input stream source is known. To concatenate more streams without binding, or without nested calls to this method, try creating a stream of streams and flat-mapping with the identity function, for example:

IntStream concat = Stream.of(s1, s2, s3, s4).flatMapToInt(s -> s);

Parameters

a:IntStream: the first stream
b:IntStream: the second stream

Returns:IntStream

the concatenation of the two input streams

count back to summary

count	back to summary
public long count() Returns the count of elements in this stream. This is a special case of a reduction and is equivalent to: `return mapToLong(e -> 1L).sum();` This is a terminal operation. API Note An implementation may choose to not execute the stream pipeline (either sequentially or in parallel) if it is capable of computing the count directly from the stream source. In such cases no source elements will be traversed and no intermediate operations will be evaluated. Behavioral parameters with side-effects, which are strongly discouraged except for harmless cases such as debugging, may be affected. For example, consider the following stream: `IntStream s = IntStream.of(1, 2, 3, 4); long count = s.peek(System.out::println).count();` The number of elements covered by the stream source is known and the intermediate operation, `peek`, does not inject into or remove elements from the stream (as may be the case for `flatMap` or `filter` operations). Thus the count is 4 and there is no need to execute the pipeline and, as a side-effect, print out the elements. Returns:long the count of elements in this stream

public long count()

Returns the count of elements in this stream. This is a special case of a reduction and is equivalent to:

return mapToLong(e -> 1L).sum();

This is a terminal operation.

API Note

An implementation may choose to not execute the stream pipeline (either sequentially or in parallel) if it is capable of computing the count directly from the stream source. In such cases no source elements will be traversed and no intermediate operations will be evaluated. Behavioral parameters with side-effects, which are strongly discouraged except for harmless cases such as debugging, may be affected. For example, consider the following stream:

IntStream s = IntStream.of(1, 2, 3, 4);
    long count = s.peek(System.out::println).count();

The number of elements covered by the stream source is known and the intermediate operation, peek, does not inject into or remove elements from the stream (as may be the case for flatMap or filter operations). Thus the count is 4 and there is no need to execute the pipeline and, as a side-effect, print out the elements.

Returns:long: the count of elements in this stream

distinct	back to summary
public IntStream distinct() Returns a stream consisting of the distinct elements of this stream. This is a stateful intermediate operation. Returns:IntStream the new stream

distinct

back to summary

public IntStream distinct()

Returns a stream consisting of the distinct elements of this stream.

This is a stateful intermediate operation.

Returns:IntStream: the new stream

dropWhile back to summary

dropWhile	back to summary
public default IntStream dropWhile(IntPredicate predicate) Returns, if this stream is ordered, a stream consisting of the remaining elements of this stream after dropping the longest prefix of elements that match the given predicate. Otherwise returns, if this stream is unordered, a stream consisting of the remaining elements of this stream after dropping a subset of elements that match the given predicate. If this stream is ordered then the longest prefix is a contiguous sequence of elements of this stream that match the given predicate. The first element of the sequence is the first element of this stream, and the element immediately following the last element of the sequence does not match the given predicate. If this stream is unordered, and some (but not all) elements of this stream match the given predicate, then the behavior of this operation is nondeterministic; it is free to drop any subset of matching elements (which includes the empty set). Independent of whether this stream is ordered or unordered if all elements of this stream match the given predicate then this operation drops all elements (the result is an empty stream), or if no elements of the stream match the given predicate then no elements are dropped (the result is the same as the input). This is a stateful intermediate operation. Implementation Specification The default implementation obtains the `spliterator` of this stream, wraps that spliterator so as to support the semantics of this operation on traversal, and returns a new stream associated with the wrapped spliterator. The returned stream preserves the execution characteristics of this stream (namely parallel or sequential execution as per `isParallel()`) but the wrapped spliterator may choose to not support splitting. When the returned stream is closed, the close handlers for both the returned and this stream are invoked. API Note While `dropWhile()` is generally a cheap operation on sequential stream pipelines, it can be quite expensive on ordered parallel pipelines, since the operation is constrained to return not just any valid prefix, but the longest prefix of elements in the encounter order. Using an unordered stream source (such as `generate(IntSupplier)`) or removing the ordering constraint with `unordered()` may result in significant speedups of `dropWhile()` in parallel pipelines, if the semantics of your situation permit. If consistency with encounter order is required, and you are experiencing poor performance or memory utilization with `dropWhile()` in parallel pipelines, switching to sequential execution with `sequential()` may improve performance. Parameters predicate:IntPredicate a non-interfering, stateless predicate to apply to elements to determine the longest prefix of elements. Returns:IntStream the new stream Since 9

public default IntStream dropWhile(IntPredicate predicate)

Returns, if this stream is ordered, a stream consisting of the remaining elements of this stream after dropping the longest prefix of elements that match the given predicate. Otherwise returns, if this stream is unordered, a stream consisting of the remaining elements of this stream after dropping a subset of elements that match the given predicate.

If this stream is ordered then the longest prefix is a contiguous sequence of elements of this stream that match the given predicate. The first element of the sequence is the first element of this stream, and the element immediately following the last element of the sequence does not match the given predicate.

If this stream is unordered, and some (but not all) elements of this stream match the given predicate, then the behavior of this operation is nondeterministic; it is free to drop any subset of matching elements (which includes the empty set).

Independent of whether this stream is ordered or unordered if all elements of this stream match the given predicate then this operation drops all elements (the result is an empty stream), or if no elements of the stream match the given predicate then no elements are dropped (the result is the same as the input).

This is a stateful intermediate operation.

Implementation Specification

The default implementation obtains the spliterator of this stream, wraps that spliterator so as to support the semantics of this operation on traversal, and returns a new stream associated with the wrapped spliterator. The returned stream preserves the execution characteristics of this stream (namely parallel or sequential execution as per isParallel()) but the wrapped spliterator may choose to not support splitting. When the returned stream is closed, the close handlers for both the returned and this stream are invoked.

API Note

While dropWhile() is generally a cheap operation on sequential stream pipelines, it can be quite expensive on ordered parallel pipelines, since the operation is constrained to return not just any valid prefix, but the longest prefix of elements in the encounter order. Using an unordered stream source (such as generate(IntSupplier)) or removing the ordering constraint with unordered() may result in significant speedups of dropWhile() in parallel pipelines, if the semantics of your situation permit. If consistency with encounter order is required, and you are experiencing poor performance or memory utilization with dropWhile() in parallel pipelines, switching to sequential execution with sequential() may improve performance.

Parameters

predicate:IntPredicate: a non-interfering, stateless predicate to apply to elements to determine the longest prefix of elements.

Returns:IntStream

the new stream

Since

empty back to summary

empty	back to summary
public static IntStream empty() Returns an empty sequential `IntStream`. Returns:IntStream an empty sequential stream

public static IntStream empty()

Returns an empty sequential IntStream.

Returns:IntStream: an empty sequential stream

filter	back to summary
public IntStream filter(IntPredicate predicate) Returns a stream consisting of the elements of this stream that match the given predicate. This is an intermediate operation. Parameters predicate:IntPredicate a non-interfering, stateless predicate to apply to each element to determine if it should be included Returns:IntStream the new stream

filter

back to summary

public IntStream filter(IntPredicate predicate)

Returns a stream consisting of the elements of this stream that match the given predicate.

This is an intermediate operation.

Parameters

predicate:IntPredicate: a non-interfering, stateless predicate to apply to each element to determine if it should be included

Returns:IntStream

the new stream

findAny back to summary

findAny	back to summary
public OptionalInt findAny() Returns an `OptionalInt` describing some element of the stream, or an empty `OptionalInt` if the stream is empty. This is a short-circuiting terminal operation. The behavior of this operation is explicitly nondeterministic; it is free to select any element in the stream. This is to allow for maximal performance in parallel operations; the cost is that multiple invocations on the same source may not return the same result. (If a stable result is desired, use `findFirst()` instead.) Returns:OptionalInt an `OptionalInt` describing some element of this stream, or an empty `OptionalInt` if the stream is empty See Also `findFirst()`

public OptionalInt findAny()

Returns an OptionalInt describing some element of the stream, or an empty OptionalInt if the stream is empty.

This is a short-circuiting terminal operation.

The behavior of this operation is explicitly nondeterministic; it is free to select any element in the stream. This is to allow for maximal performance in parallel operations; the cost is that multiple invocations on the same source may not return the same result. (If a stable result is desired, use findFirst() instead.)

Returns:OptionalInt: an OptionalInt describing some element of this stream, or an empty OptionalInt if the stream is empty
See Also: findFirst()

findFirst back to summary

findFirst	back to summary
public OptionalInt findFirst() Returns an `OptionalInt` describing the first element of this stream, or an empty `OptionalInt` if the stream is empty. If the stream has no encounter order, then any element may be returned. This is a short-circuiting terminal operation. Returns:OptionalInt an `OptionalInt` describing the first element of this stream, or an empty `OptionalInt` if the stream is empty

public OptionalInt findFirst()

Returns an OptionalInt describing the first element of this stream, or an empty OptionalInt if the stream is empty. If the stream has no encounter order, then any element may be returned.

This is a short-circuiting terminal operation.

Returns:OptionalInt: an OptionalInt describing the first element of this stream, or an empty OptionalInt if the stream is empty

flatMap back to summary

flatMap	back to summary
public IntStream flatMap(IntFunction<? extends IntStream> mapper) Returns a stream consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Each mapped stream is `closed` after its contents have been placed into this stream. (If a mapped stream is `null` an empty stream is used, instead.) This is an intermediate operation. Parameters mapper:IntFunction<? extends IntStream> a non-interfering, stateless function to apply to each element which produces an `IntStream` of new values Returns:IntStream the new stream See Also `Stream#flatMap(Function)`

public IntStream flatMap(IntFunction<? extends IntStream> mapper)

Returns a stream consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Each mapped stream is closed after its contents have been placed into this stream. (If a mapped stream is null an empty stream is used, instead.)

This is an intermediate operation.

Parameters

mapper:IntFunction<? extends IntStream>: a non-interfering, stateless function to apply to each element which produces an IntStream of new values

Returns:IntStream

the new stream

See Also

Stream#flatMap(Function)

forEach	back to summary
public void forEach(IntConsumer action) Performs an action for each element of this stream. This is a terminal operation. For parallel stream pipelines, this operation does not guarantee to respect the encounter order of the stream, as doing so would sacrifice the benefit of parallelism. For any given element, the action may be performed at whatever time and in whatever thread the library chooses. If the action accesses shared state, it is responsible for providing the required synchronization. Parameters action:IntConsumer a non-interfering action to perform on the elements

forEach

back to summary

public void forEach(IntConsumer action)

Performs an action for each element of this stream.

This is a terminal operation.

For parallel stream pipelines, this operation does not guarantee to respect the encounter order of the stream, as doing so would sacrifice the benefit of parallelism. For any given element, the action may be performed at whatever time and in whatever thread the library chooses. If the action accesses shared state, it is responsible for providing the required synchronization.

Parameters

action:IntConsumer: a non-interfering action to perform on the elements

forEachOrdered back to summary

forEachOrdered	back to summary
public void forEachOrdered(IntConsumer action) Performs an action for each element of this stream, guaranteeing that each element is processed in encounter order for streams that have a defined encounter order. This is a terminal operation. Parameters action:IntConsumer a non-interfering action to perform on the elements See Also `forEach(IntConsumer)`

public void forEachOrdered(IntConsumer action)

Performs an action for each element of this stream, guaranteeing that each element is processed in encounter order for streams that have a defined encounter order.

This is a terminal operation.

Parameters

action:IntConsumer: a non-interfering action to perform on the elements

See Also

forEach(IntConsumer)

generate back to summary

generate	back to summary
public static IntStream generate(IntSupplier s) Returns an infinite sequential unordered stream where each element is generated by the provided `IntSupplier`. This is suitable for generating constant streams, streams of random elements, etc. Parameters s:IntSupplier the `IntSupplier` for generated elements Returns:IntStream a new infinite sequential unordered `IntStream`

public static IntStream generate(IntSupplier s)

Returns an infinite sequential unordered stream where each element is generated by the provided IntSupplier. This is suitable for generating constant streams, streams of random elements, etc.

Parameters

s:IntSupplier: the IntSupplier for generated elements

Returns:IntStream

a new infinite sequential unordered IntStream

iterate back to summary

iterate	back to summary
public static IntStream iterate(final int seed, final IntUnaryOperator f) Returns an infinite sequential ordered `IntStream` produced by iterative application of a function `f` to an initial element `seed`, producing a `Stream` consisting of `seed`, `f(seed)`, `f(f(seed))`, etc. The first element (position `0`) in the `IntStream` will be the provided `seed`. For `n > 0`, the element at position `n`, will be the result of applying the function `f` to the element at position `n - 1`. The action of applying `f` for one element happens-before the action of applying `f` for subsequent elements. For any given element the action may be performed in whatever thread the library chooses. Parameters seed:int the initial element f:IntUnaryOperator a function to be applied to the previous element to produce a new element Returns:IntStream a new sequential `IntStream`

public static IntStream iterate(final int seed, final IntUnaryOperator f)

Returns an infinite sequential ordered IntStream produced by iterative application of a function f to an initial element seed, producing a Stream consisting of seed, f(seed), f(f(seed)), etc.

The first element (position 0) in the IntStream will be the provided seed. For n > 0, the element at position n, will be the result of applying the function f to the element at position n - 1.

The action of applying f for one element happens-before the action of applying f for subsequent elements. For any given element the action may be performed in whatever thread the library chooses.

Parameters

seed:int: the initial element
f:IntUnaryOperator: a function to be applied to the previous element to produce a new element

Returns:IntStream

a new sequential IntStream

iterate back to summary

iterate	back to summary
public static IntStream iterate(int seed, IntPredicate hasNext, IntUnaryOperator next) Returns a sequential ordered `IntStream` produced by iterative application of the given `next` function to an initial element, conditioned on satisfying the given `hasNext` predicate. The stream terminates as soon as the `hasNext` predicate returns false. `IntStream.iterate` should produce the same sequence of elements as produced by the corresponding for-loop: `for (int index=seed; hasNext.test(index); index = next.applyAsInt(index)) { ... }` The resulting sequence may be empty if the `hasNext` predicate does not hold on the seed value. Otherwise the first element will be the supplied `seed` value, the next element (if present) will be the result of applying the `next` function to the `seed` value, and so on iteratively until the `hasNext` predicate indicates that the stream should terminate. The action of applying the `hasNext` predicate to an element happens-before the action of applying the `next` function to that element. The action of applying the `next` function for one element happens-before the action of applying the `hasNext` predicate for subsequent elements. For any given element an action may be performed in whatever thread the library chooses. Parameters seed:int the initial element hasNext:IntPredicate a predicate to apply to elements to determine when the stream must terminate. next:IntUnaryOperator a function to be applied to the previous element to produce a new element Returns:IntStream a new sequential `IntStream` Since 9

public static IntStream iterate(int seed, IntPredicate hasNext, IntUnaryOperator next)

Returns a sequential ordered IntStream produced by iterative application of the given next function to an initial element, conditioned on satisfying the given hasNext predicate. The stream terminates as soon as the hasNext predicate returns false.

IntStream.iterate should produce the same sequence of elements as produced by the corresponding for-loop:

for (int index=seed; hasNext.test(index); index = next.applyAsInt(index)) {
        ...
    }

The resulting sequence may be empty if the hasNext predicate does not hold on the seed value. Otherwise the first element will be the supplied seed value, the next element (if present) will be the result of applying the next function to the seed value, and so on iteratively until the hasNext predicate indicates that the stream should terminate.

The action of applying the hasNext predicate to an element happens-before the action of applying the next function to that element. The action of applying the next function for one element happens-before the action of applying the hasNext predicate for subsequent elements. For any given element an action may be performed in whatever thread the library chooses.

Parameters

seed:int: the initial element
hasNext:IntPredicate: a predicate to apply to elements to determine when the stream must terminate.
next:IntUnaryOperator: a function to be applied to the previous element to produce a new element

Returns:IntStream

a new sequential IntStream

Since

iterator	back to summary
public PrimitiveIterator.OfInt iterator() Redeclares java.util.stream.BaseStream.iterator. Doc from java.util.stream.BaseStream.iterator. Returns an iterator for the elements of this stream. This is a terminal operation. Returns:PrimitiveIterator.OfInt the element iterator for this stream Annotations @Override

iterator

back to summary

public PrimitiveIterator.OfInt iterator()

Redeclares java.util.stream.BaseStream.iterator.

Doc from java.util.stream.BaseStream.iterator.

Returns an iterator for the elements of this stream.

This is a terminal operation.

Returns:PrimitiveIterator.OfInt

the element iterator for this stream

Annotations

@Override

limit back to summary

limit	back to summary
public IntStream limit(long maxSize) Returns a stream consisting of the elements of this stream, truncated to be no longer than `maxSize` in length. This is a short-circuiting stateful intermediate operation. API Note While `limit()` is generally a cheap operation on sequential stream pipelines, it can be quite expensive on ordered parallel pipelines, especially for large values of `maxSize`, since `limit(n)` is constrained to return not just any n elements, but the first n elements in the encounter order. Using an unordered stream source (such as `generate(IntSupplier)`) or removing the ordering constraint with `unordered()` may result in significant speedups of `limit()` in parallel pipelines, if the semantics of your situation permit. If consistency with encounter order is required, and you are experiencing poor performance or memory utilization with `limit()` in parallel pipelines, switching to sequential execution with `sequential()` may improve performance. Parameters maxSize:long the number of elements the stream should be limited to Returns:IntStream the new stream Exceptions IllegalArgumentException: if `maxSize` is negative

public IntStream limit(long maxSize)

Returns a stream consisting of the elements of this stream, truncated to be no longer than maxSize in length.

This is a short-circuiting stateful intermediate operation.

API Note

While limit() is generally a cheap operation on sequential stream pipelines, it can be quite expensive on ordered parallel pipelines, especially for large values of maxSize, since limit(n) is constrained to return not just any n elements, but the first n elements in the encounter order. Using an unordered stream source (such as generate(IntSupplier)) or removing the ordering constraint with unordered() may result in significant speedups of limit() in parallel pipelines, if the semantics of your situation permit. If consistency with encounter order is required, and you are experiencing poor performance or memory utilization with limit() in parallel pipelines, switching to sequential execution with sequential() may improve performance.

Parameters

maxSize:long: the number of elements the stream should be limited to

Returns:IntStream

the new stream

Exceptions

IllegalArgumentException:: if maxSize is negative

map	back to summary
public IntStream map(IntUnaryOperator mapper) Returns a stream consisting of the results of applying the given function to the elements of this stream. This is an intermediate operation. Parameters mapper:IntUnaryOperator a non-interfering, stateless function to apply to each element Returns:IntStream the new stream

map

back to summary

public IntStream map(IntUnaryOperator mapper)

Returns a stream consisting of the results of applying the given function to the elements of this stream.

This is an intermediate operation.

Parameters

mapper:IntUnaryOperator: a non-interfering, stateless function to apply to each element

Returns:IntStream

the new stream

mapMulti back to summary

mapMulti	back to summary
public default IntStream mapMulti(IntStream.IntMapMultiConsumer mapper) Returns a stream consisting of the results of replacing each element of this stream with multiple elements, specifically zero or more elements. Replacement is performed by applying the provided mapping function to each element in conjunction with a consumer argument that accepts replacement elements. The mapping function calls the consumer zero or more times to provide the replacement elements. This is an intermediate operation. If the consumer argument is used outside the scope of its application to the mapping function, the results are undefined. Implementation Specification The default implementation invokes `flatMap` on this stream, passing a function that behaves as follows. First, it calls the mapper function with an `IntConsumer` that accumulates replacement elements into a newly created internal buffer. When the mapper function returns, it creates an `IntStream` from the internal buffer. Finally, it returns this stream to `flatMap`. Parameters mapper:IntStream.IntMapMultiConsumer a non-interfering, stateless function that generates replacement elements Returns:IntStream the new stream Since 16 See Also `Stream.mapMulti`

public default IntStream mapMulti(IntStream.IntMapMultiConsumer mapper)

Returns a stream consisting of the results of replacing each element of this stream with multiple elements, specifically zero or more elements. Replacement is performed by applying the provided mapping function to each element in conjunction with a consumer argument that accepts replacement elements. The mapping function calls the consumer zero or more times to provide the replacement elements.

This is an intermediate operation.

If the consumer argument is used outside the scope of its application to the mapping function, the results are undefined.

Implementation Specification

The default implementation invokes flatMap on this stream, passing a function that behaves as follows. First, it calls the mapper function with an IntConsumer that accumulates replacement elements into a newly created internal buffer. When the mapper function returns, it creates an IntStream from the internal buffer. Finally, it returns this stream to flatMap.

Parameters

mapper:IntStream.IntMapMultiConsumer: a non-interfering, stateless function that generates replacement elements

Returns:IntStream

the new stream

Since

See Also

Stream.mapMulti

mapToDouble back to summary

mapToDouble	back to summary
public DoubleStream mapToDouble(IntToDoubleFunction mapper) Returns a `DoubleStream` consisting of the results of applying the given function to the elements of this stream. This is an intermediate operation. Parameters mapper:IntToDoubleFunction a non-interfering, stateless function to apply to each element Returns:DoubleStream the new stream

public DoubleStream mapToDouble(IntToDoubleFunction mapper)

Returns a DoubleStream consisting of the results of applying the given function to the elements of this stream.

This is an intermediate operation.

Parameters

mapper:IntToDoubleFunction: a non-interfering, stateless function to apply to each element

Returns:DoubleStream

the new stream

mapToLong back to summary

mapToLong	back to summary
public LongStream mapToLong(IntToLongFunction mapper) Returns a `LongStream` consisting of the results of applying the given function to the elements of this stream. This is an intermediate operation. Parameters mapper:IntToLongFunction a non-interfering, stateless function to apply to each element Returns:LongStream the new stream

public LongStream mapToLong(IntToLongFunction mapper)

Returns a LongStream consisting of the results of applying the given function to the elements of this stream.

This is an intermediate operation.

Parameters

mapper:IntToLongFunction: a non-interfering, stateless function to apply to each element

Returns:LongStream

the new stream

mapToObj back to summary

mapToObj	back to summary
public <U> Stream<U> mapToObj(IntFunction<? extends U> mapper) Returns an object-valued `Stream` consisting of the results of applying the given function to the elements of this stream. This is an intermediate operation. Parameters <U> the element type of the new stream mapper:IntFunction<? extends U> a non-interfering, stateless function to apply to each element Returns:Stream<U> the new stream

public <U> Stream<U> mapToObj(IntFunction<? extends U> mapper)

Returns an object-valued Stream consisting of the results of applying the given function to the elements of this stream.

This is an intermediate operation.

Parameters

<U>: the element type of the new stream
mapper:IntFunction<? extends U>: a non-interfering, stateless function to apply to each element

Returns:Stream<U>

the new stream

max back to summary

max	back to summary
public OptionalInt max() Returns an `OptionalInt` describing the maximum element of this stream, or an empty optional if this stream is empty. This is a special case of a reduction and is equivalent to: `return reduce(Integer::max);` This is a terminal operation. Returns:OptionalInt an `OptionalInt` containing the maximum element of this stream, or an empty `OptionalInt` if the stream is empty

public OptionalInt max()

Returns an OptionalInt describing the maximum element of this stream, or an empty optional if this stream is empty. This is a special case of a reduction and is equivalent to:

return reduce(Integer::max);

This is a terminal operation.

Returns:OptionalInt: an OptionalInt containing the maximum element of this stream, or an empty OptionalInt if the stream is empty

min back to summary

min	back to summary
public OptionalInt min() Returns an `OptionalInt` describing the minimum element of this stream, or an empty optional if this stream is empty. This is a special case of a reduction and is equivalent to: `return reduce(Integer::min);` This is a terminal operation. Returns:OptionalInt an `OptionalInt` containing the minimum element of this stream, or an empty `OptionalInt` if the stream is empty

public OptionalInt min()

Returns an OptionalInt describing the minimum element of this stream, or an empty optional if this stream is empty. This is a special case of a reduction and is equivalent to:

return reduce(Integer::min);

This is a terminal operation.

Returns:OptionalInt: an OptionalInt containing the minimum element of this stream, or an empty OptionalInt if the stream is empty

noneMatch back to summary

noneMatch	back to summary
public boolean noneMatch(IntPredicate predicate) Returns whether no elements of this stream match the provided predicate. May not evaluate the predicate on all elements if not necessary for determining the result. If the stream is empty then `true` is returned and the predicate is not evaluated. This is a short-circuiting terminal operation. API Note This method evaluates the universal quantification of the negated predicate over the elements of the stream (for all x ~P(x)). If the stream is empty, the quantification is said to be vacuously satisfied and is always `true`, regardless of P(x). Parameters predicate:IntPredicate a non-interfering, stateless predicate to apply to elements of this stream Returns:boolean `true` if either no elements of the stream match the provided predicate or the stream is empty, otherwise `false`

public boolean noneMatch(IntPredicate predicate)

Returns whether no elements of this stream match the provided predicate. May not evaluate the predicate on all elements if not necessary for determining the result. If the stream is empty then true is returned and the predicate is not evaluated.

This is a short-circuiting terminal operation.

API Note

This method evaluates the universal quantification of the negated predicate over the elements of the stream (for all x ~P(x)). If the stream is empty, the quantification is said to be vacuously satisfied and is always true, regardless of P(x).

Parameters

predicate:IntPredicate: a non-interfering, stateless predicate to apply to elements of this stream

Returns:boolean

true if either no elements of the stream match the provided predicate or the stream is empty, otherwise false

of back to summary

of	back to summary
public static IntStream of(int t) Returns a sequential `IntStream` containing a single element. Parameters t:int the single element Returns:IntStream a singleton sequential stream

public static IntStream of(int t)

Returns a sequential IntStream containing a single element.

Parameters

t:int: the single element

Returns:IntStream

a singleton sequential stream

of	back to summary
public static IntStream of(int... values) Returns a sequential ordered stream whose elements are the specified values. Parameters values:int[] the elements of the new stream Returns:IntStream the new stream

back to summary

public static IntStream of(int... values)

Returns a sequential ordered stream whose elements are the specified values.

Parameters

values:int[]: the elements of the new stream

Returns:IntStream

the new stream

parallel	back to summary
public IntStream parallel() Redeclares java.util.stream.BaseStream.parallel. Doc from java.util.stream.BaseStream.parallel. Returns an equivalent stream that is parallel. May return itself, either because the stream was already parallel, or because the underlying stream state was modified to be parallel. This is an intermediate operation. Returns:IntStream a parallel stream Annotations @Override

parallel

back to summary

public IntStream parallel()

Redeclares java.util.stream.BaseStream.parallel.

Doc from java.util.stream.BaseStream.parallel.

Returns an equivalent stream that is parallel. May return itself, either because the stream was already parallel, or because the underlying stream state was modified to be parallel.

This is an intermediate operation.

Returns:IntStream

a parallel stream

Annotations

@Override

peek back to summary

peek	back to summary
public IntStream peek(IntConsumer action) Returns a stream consisting of the elements of this stream, additionally performing the provided action on each element as elements are consumed from the resulting stream. This is an intermediate operation. For parallel stream pipelines, the action may be called at whatever time and in whatever thread the element is made available by the upstream operation. If the action modifies shared state, it is responsible for providing the required synchronization. API Note This method exists mainly to support debugging, where you want to see the elements as they flow past a certain point in a pipeline: `IntStream.of(1, 2, 3, 4) .filter(e -> e > 2) .peek(e -> System.out.println("Filtered value: " + e)) .map(e -> e * e) .peek(e -> System.out.println("Mapped value: " + e)) .sum();` In cases where the stream implementation is able to optimize away the production of some or all the elements (such as with short-circuiting operations like `findFirst`, or in the example described in `count`), the action will not be invoked for those elements. Parameters action:IntConsumer a non-interfering action to perform on the elements as they are consumed from the stream Returns:IntStream the new stream

public IntStream peek(IntConsumer action)

Returns a stream consisting of the elements of this stream, additionally performing the provided action on each element as elements are consumed from the resulting stream.

This is an intermediate operation.

For parallel stream pipelines, the action may be called at whatever time and in whatever thread the element is made available by the upstream operation. If the action modifies shared state, it is responsible for providing the required synchronization.

API Note

This method exists mainly to support debugging, where you want to see the elements as they flow past a certain point in a pipeline:

IntStream.of(1, 2, 3, 4)
        .filter(e -> e > 2)
        .peek(e -> System.out.println("Filtered value: " + e))
        .map(e -> e * e)
        .peek(e -> System.out.println("Mapped value: " + e))
        .sum();

In cases where the stream implementation is able to optimize away the production of some or all the elements (such as with short-circuiting operations like findFirst, or in the example described in count), the action will not be invoked for those elements.

Parameters

action:IntConsumer: a non-interfering action to perform on the elements as they are consumed from the stream

Returns:IntStream

the new stream

range back to summary

range	back to summary
public static IntStream range(int startInclusive, int endExclusive) Returns a sequential ordered `IntStream` from `startInclusive` (inclusive) to `endExclusive` (exclusive) by an incremental step of `1`. API Note An equivalent sequence of increasing values can be produced sequentially using a `for` loop as follows: `for (int i = startInclusive; i < endExclusive ; i++) { ... }` Parameters startInclusive:int the (inclusive) initial value endExclusive:int the exclusive upper bound Returns:IntStream a sequential `IntStream` for the range of `int` elements

public static IntStream range(int startInclusive, int endExclusive)

Returns a sequential ordered IntStream from startInclusive (inclusive) to endExclusive (exclusive) by an incremental step of 1.

API Note

An equivalent sequence of increasing values can be produced sequentially using a for loop as follows:

for (int i = startInclusive; i < endExclusive ; i++) { ... }

Parameters

startInclusive:int: the (inclusive) initial value
endExclusive:int: the exclusive upper bound

Returns:IntStream

a sequential IntStream for the range of int elements

rangeClosed back to summary

rangeClosed	back to summary
public static IntStream rangeClosed(int startInclusive, int endInclusive) Returns a sequential ordered `IntStream` from `startInclusive` (inclusive) to `endInclusive` (inclusive) by an incremental step of `1`. API Note An equivalent sequence of increasing values can be produced sequentially using a `for` loop as follows: `for (int i = startInclusive; i <= endInclusive ; i++) { ... }` Parameters startInclusive:int the (inclusive) initial value endInclusive:int the inclusive upper bound Returns:IntStream a sequential `IntStream` for the range of `int` elements

public static IntStream rangeClosed(int startInclusive, int endInclusive)

Returns a sequential ordered IntStream from startInclusive (inclusive) to endInclusive (inclusive) by an incremental step of 1.

API Note

An equivalent sequence of increasing values can be produced sequentially using a for loop as follows:

for (int i = startInclusive; i <= endInclusive ; i++) { ... }

Parameters

startInclusive:int: the (inclusive) initial value
endInclusive:int: the inclusive upper bound

Returns:IntStream

a sequential IntStream for the range of int elements

reduce back to summary

reduce	back to summary
public int reduce(int identity, IntBinaryOperator op) Performs a reduction on the elements of this stream, using the provided identity value and an associative accumulation function, and returns the reduced value. This is equivalent to: `int result = identity; for (int element : this stream) result = accumulator.applyAsInt(result, element) return result;` but is not constrained to execute sequentially. The `identity` value must be an identity for the accumulator function. This means that for all `x`, `accumulator.apply(identity, x)` is equal to `x`. The `accumulator` function must be an associative function. This is a terminal operation. API Note Sum, min and max are all special cases of reduction that can be expressed using this method. For example, summing a stream can be expressed as: `int sum = integers.reduce(0, (a, b) -> a+b);` or more compactly: `int sum = integers.reduce(0, Integer::sum);` While this may seem a more roundabout way to perform an aggregation compared to simply mutating a running total in a loop, reduction operations parallelize more gracefully, without needing additional synchronization and with greatly reduced risk of data races. Parameters identity:int the identity value for the accumulating function op:IntBinaryOperator an associative, non-interfering, stateless function for combining two values Returns:int the result of the reduction See Also `sum()`, `min()`, `max()`, `average()`

public int reduce(int identity, IntBinaryOperator op)

Performs a reduction on the elements of this stream, using the provided identity value and an associative accumulation function, and returns the reduced value. This is equivalent to:

int result = identity;
    for (int element : this stream)
        result = accumulator.applyAsInt(result, element)
    return result;

but is not constrained to execute sequentially.

The identity value must be an identity for the accumulator function. This means that for all x, accumulator.apply(identity, x) is equal to x. The accumulator function must be an associative function.

This is a terminal operation.

API Note

Sum, min and max are all special cases of reduction that can be expressed using this method. For example, summing a stream can be expressed as:

int sum = integers.reduce(0, (a, b) -> a+b);

or more compactly:

int sum = integers.reduce(0, Integer::sum);

While this may seem a more roundabout way to perform an aggregation compared to simply mutating a running total in a loop, reduction operations parallelize more gracefully, without needing additional synchronization and with greatly reduced risk of data races.

Parameters

identity:int: the identity value for the accumulating function
op:IntBinaryOperator: an associative, non-interfering, stateless function for combining two values

Returns:int

the result of the reduction

See Also

sum(), min(), max(), average()

reduce back to summary

reduce	back to summary
public OptionalInt reduce(IntBinaryOperator op) Performs a reduction on the elements of this stream, using an associative accumulation function, and returns an `OptionalInt` describing the reduced value, if any. This is equivalent to: `boolean foundAny = false; int result = null; for (int element : this stream) { if (!foundAny) { foundAny = true; result = element; } else result = accumulator.applyAsInt(result, element); } return foundAny ? OptionalInt.of(result) : OptionalInt.empty();` but is not constrained to execute sequentially. The `accumulator` function must be an associative function. This is a terminal operation. Parameters op:IntBinaryOperator an associative, non-interfering, stateless function for combining two values Returns:OptionalInt the result of the reduction See Also `reduce(int, IntBinaryOperator)`

public OptionalInt reduce(IntBinaryOperator op)

Performs a reduction on the elements of this stream, using an associative accumulation function, and returns an OptionalInt describing the reduced value, if any. This is equivalent to:

boolean foundAny = false;
    int result = null;
    for (int element : this stream) {
        if (!foundAny) {
            foundAny = true;
            result = element;
        }
        else
            result = accumulator.applyAsInt(result, element);
    }
    return foundAny ? OptionalInt.of(result) : OptionalInt.empty();

but is not constrained to execute sequentially.

The accumulator function must be an associative function.

This is a terminal operation.

Parameters

op:IntBinaryOperator: an associative, non-interfering, stateless function for combining two values

Returns:OptionalInt

the result of the reduction

See Also

reduce(int, IntBinaryOperator)

sequential	back to summary
public IntStream sequential() Redeclares java.util.stream.BaseStream.sequential. Doc from java.util.stream.BaseStream.sequential. Returns an equivalent stream that is sequential. May return itself, either because the stream was already sequential, or because the underlying stream state was modified to be sequential. This is an intermediate operation. Returns:IntStream a sequential stream Annotations @Override

sequential

back to summary

public IntStream sequential()

Redeclares java.util.stream.BaseStream.sequential.

Doc from java.util.stream.BaseStream.sequential.

Returns an equivalent stream that is sequential. May return itself, either because the stream was already sequential, or because the underlying stream state was modified to be sequential.

This is an intermediate operation.

Returns:IntStream

a sequential stream

Annotations

@Override

skip back to summary

skip	back to summary
public IntStream skip(long n) Returns a stream consisting of the remaining elements of this stream after discarding the first `n` elements of the stream. If this stream contains fewer than `n` elements then an empty stream will be returned. This is a stateful intermediate operation. API Note While `skip()` is generally a cheap operation on sequential stream pipelines, it can be quite expensive on ordered parallel pipelines, especially for large values of `n`, since `skip(n)` is constrained to skip not just any n elements, but the first n elements in the encounter order. Using an unordered stream source (such as `generate(IntSupplier)`) or removing the ordering constraint with `unordered()` may result in significant speedups of `skip()` in parallel pipelines, if the semantics of your situation permit. If consistency with encounter order is required, and you are experiencing poor performance or memory utilization with `skip()` in parallel pipelines, switching to sequential execution with `sequential()` may improve performance. Parameters n:long the number of leading elements to skip Returns:IntStream the new stream Exceptions IllegalArgumentException: if `n` is negative

public IntStream skip(long n)

Returns a stream consisting of the remaining elements of this stream after discarding the first n elements of the stream. If this stream contains fewer than n elements then an empty stream will be returned.

This is a stateful intermediate operation.

API Note

While skip() is generally a cheap operation on sequential stream pipelines, it can be quite expensive on ordered parallel pipelines, especially for large values of n, since skip(n) is constrained to skip not just any n elements, but the first n elements in the encounter order. Using an unordered stream source (such as generate(IntSupplier)) or removing the ordering constraint with unordered() may result in significant speedups of skip() in parallel pipelines, if the semantics of your situation permit. If consistency with encounter order is required, and you are experiencing poor performance or memory utilization with skip() in parallel pipelines, switching to sequential execution with sequential() may improve performance.

Parameters

n:long: the number of leading elements to skip

Returns:IntStream

the new stream

Exceptions

IllegalArgumentException:: if n is negative

sorted	back to summary
public IntStream sorted() Returns a stream consisting of the elements of this stream in sorted order. This is a stateful intermediate operation. Returns:IntStream the new stream

sorted

back to summary

public IntStream sorted()

Returns a stream consisting of the elements of this stream in sorted order.

This is a stateful intermediate operation.

Returns:IntStream: the new stream

spliterator	back to summary
public Spliterator.OfInt spliterator() Redeclares java.util.stream.BaseStream.spliterator. Doc from java.util.stream.BaseStream.spliterator. Returns a spliterator for the elements of this stream. This is a terminal operation. Returns:Spliterator.OfInt the element spliterator for this stream Annotations @Override

spliterator

back to summary

public Spliterator.OfInt spliterator()

Redeclares java.util.stream.BaseStream.spliterator.

Doc from java.util.stream.BaseStream.spliterator.

Returns a spliterator for the elements of this stream.

This is a terminal operation.

Returns:Spliterator.OfInt

the element spliterator for this stream

Annotations

@Override

sum back to summary

sum	back to summary
public int sum() Returns the sum of elements in this stream. This is a special case of a reduction and is equivalent to: `return reduce(0, Integer::sum);` This is a terminal operation. Returns:int the sum of elements in this stream

public int sum()

Returns the sum of elements in this stream. This is a special case of a reduction and is equivalent to:

return reduce(0, Integer::sum);

This is a terminal operation.

Returns:int: the sum of elements in this stream

summaryStatistics back to summary

summaryStatistics	back to summary
public IntSummaryStatistics summaryStatistics() Returns an `IntSummaryStatistics` describing various summary data about the elements of this stream. This is a special case of a reduction. This is a terminal operation. Returns:IntSummaryStatistics an `IntSummaryStatistics` describing various summary data about the elements of this stream

public IntSummaryStatistics summaryStatistics()

Returns an IntSummaryStatistics describing various summary data about the elements of this stream. This is a special case of a reduction.

This is a terminal operation.

Returns:IntSummaryStatistics: an IntSummaryStatistics describing various summary data about the elements of this stream

takeWhile back to summary

takeWhile	back to summary
public default IntStream takeWhile(IntPredicate predicate) Returns, if this stream is ordered, a stream consisting of the longest prefix of elements taken from this stream that match the given predicate. Otherwise returns, if this stream is unordered, a stream consisting of a subset of elements taken from this stream that match the given predicate. If this stream is ordered then the longest prefix is a contiguous sequence of elements of this stream that match the given predicate. The first element of the sequence is the first element of this stream, and the element immediately following the last element of the sequence does not match the given predicate. If this stream is unordered, and some (but not all) elements of this stream match the given predicate, then the behavior of this operation is nondeterministic; it is free to take any subset of matching elements (which includes the empty set). Independent of whether this stream is ordered or unordered if all elements of this stream match the given predicate then this operation takes all elements (the result is the same as the input), or if no elements of the stream match the given predicate then no elements are taken (the result is an empty stream). This is a short-circuiting stateful intermediate operation. Implementation Specification The default implementation obtains the `spliterator` of this stream, wraps that spliterator so as to support the semantics of this operation on traversal, and returns a new stream associated with the wrapped spliterator. The returned stream preserves the execution characteristics of this stream (namely parallel or sequential execution as per `isParallel()`) but the wrapped spliterator may choose to not support splitting. When the returned stream is closed, the close handlers for both the returned and this stream are invoked. API Note While `takeWhile()` is generally a cheap operation on sequential stream pipelines, it can be quite expensive on ordered parallel pipelines, since the operation is constrained to return not just any valid prefix, but the longest prefix of elements in the encounter order. Using an unordered stream source (such as `generate(IntSupplier)`) or removing the ordering constraint with `unordered()` may result in significant speedups of `takeWhile()` in parallel pipelines, if the semantics of your situation permit. If consistency with encounter order is required, and you are experiencing poor performance or memory utilization with `takeWhile()` in parallel pipelines, switching to sequential execution with `sequential()` may improve performance. Parameters predicate:IntPredicate a non-interfering, stateless predicate to apply to elements to determine the longest prefix of elements. Returns:IntStream the new stream Since 9

public default IntStream takeWhile(IntPredicate predicate)

Returns, if this stream is ordered, a stream consisting of the longest prefix of elements taken from this stream that match the given predicate. Otherwise returns, if this stream is unordered, a stream consisting of a subset of elements taken from this stream that match the given predicate.

If this stream is unordered, and some (but not all) elements of this stream match the given predicate, then the behavior of this operation is nondeterministic; it is free to take any subset of matching elements (which includes the empty set).

Independent of whether this stream is ordered or unordered if all elements of this stream match the given predicate then this operation takes all elements (the result is the same as the input), or if no elements of the stream match the given predicate then no elements are taken (the result is an empty stream).

This is a short-circuiting stateful intermediate operation.

Implementation Specification

API Note

While takeWhile() is generally a cheap operation on sequential stream pipelines, it can be quite expensive on ordered parallel pipelines, since the operation is constrained to return not just any valid prefix, but the longest prefix of elements in the encounter order. Using an unordered stream source (such as generate(IntSupplier)) or removing the ordering constraint with unordered() may result in significant speedups of takeWhile() in parallel pipelines, if the semantics of your situation permit. If consistency with encounter order is required, and you are experiencing poor performance or memory utilization with takeWhile() in parallel pipelines, switching to sequential execution with sequential() may improve performance.

Parameters

predicate:IntPredicate: a non-interfering, stateless predicate to apply to elements to determine the longest prefix of elements.

Returns:IntStream

the new stream

Since

toArray	back to summary
public int[] toArray() Returns an array containing the elements of this stream. This is a terminal operation. Returns:int[] an array containing the elements of this stream

toArray

back to summary

public int[] toArray()

Returns an array containing the elements of this stream.

This is a terminal operation.

Returns:int[]: an array containing the elements of this stream

public Interface IntStream

Nested and Inner Type Summary

Method Summary

Method Detail

public Interface IntStream.Builder

Method Summary

Method Detail

public Interface IntStream.IntMapMultiConsumer

Method Summary

Method Detail

Modifier and Type	Method and Description
public void	accept(int the input argument t) Redeclares java.util.function.IntConsumer.accept. Adds an element to the stream being built.
public default IntStream.Builder	Returns: `this` builder add(int the element to add t) Adds an element to the stream being built.
public IntStream	Returns: the built stream build() Builds the stream, transitioning this builder to the built state.