OpenJDK 1.23 · java.util.AbstractCollection · APIdia, the JavaDoc alternative

Access	Constructor and Description
protected	AbstractCollection() Sole constructor.

Modifier and Type	Method and Description
public boolean	add(E element whose presence in this collection is to be ensured e) Implements java.util.Collection.add. Ensures that this collection contains the specified element (optional operation).
public boolean	addAll(Collection<? extends E> collection containing elements to be added to this collection c) Implements java.util.Collection.addAll. Adds all of the elements in the specified collection to this collection (optional operation).
public void	clear() Implements java.util.Collection.clear. Removes all of the elements from this collection (optional operation).
public boolean	contains(Object element whose presence in this collection is to be tested o) Implements java.util.Collection.contains. Returns `true` if this collection contains the specified element.
public boolean	containsAll(Collection<?> collection to be checked for containment in this collection c) Implements java.util.Collection.containsAll. Returns `true` if this collection contains all of the elements in the specified collection.
private static <T> T[]	Returns: array containing the elements in the given array, plus any further elements returned by the iterator, trimmed to size finishToArray(T[] the array, replete with previously stored elements r, Iterator<?> the in-progress iterator over this collection it) Reallocates the array being used within toArray when the iterator returned more elements than expected, and finishes filling it from the iterator.
public boolean	isEmpty() Implements java.util.Collection.isEmpty. Returns `true` if this collection contains no elements.
public abstract Iterator<E>	Returns: an iterator over the elements contained in this collection iterator() Redeclares java.util.Collection.iterator. Returns an iterator over the elements contained in this collection.
public boolean	remove(Object element to be removed from this collection, if present o) Implements java.util.Collection.remove. Removes a single instance of the specified element from this collection, if it is present (optional operation).
public boolean	removeAll(Collection<?> collection containing elements to be removed from this collection c) Implements java.util.Collection.removeAll. Removes all of this collection's elements that are also contained in the specified collection (optional operation).
public boolean	retainAll(Collection<?> collection containing elements to be retained in this collection c) Implements java.util.Collection.retainAll. Retains only the elements in this collection that are contained in the specified collection (optional operation).
public abstract int	size() Redeclares java.util.Collection.size. Returns the number of elements in this collection.
public Object[]	toArray() Implements java.util.Collection.toArray. Returns an array containing all of the elements in this collection.
public <T> T[]	toArray(T[] the array into which the elements of this collection are to be stored, if it is big enough; otherwise, a new array of the same runtime type is allocated for this purpose. a) Implements java.util.Collection.toArray. Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array.
public String	Returns: a string representation of this collection toString() Overrides java.lang.Object.toString. Returns a string representation of this collection.

AbstractCollection	back to summary
protected AbstractCollection() Sole constructor. (For invocation by subclass constructors, typically implicit.)

Method Detail

add back to summary

add	back to summary
public boolean add(E e) Implements java.util.Collection.add. Doc from java.util.Collection.add. Ensures that this collection contains the specified element (optional operation). Returns `true` if this collection changed as a result of the call. (Returns `false` if this collection does not permit duplicates and already contains the specified element.) Collections that support this operation may place limitations on what elements may be added to this collection. In particular, some collections will refuse to add `null` elements, and others will impose restrictions on the type of elements that may be added. Collection classes should clearly specify in their documentation any restrictions on what elements may be added. If a collection refuses to add a particular element for any reason other than that it already contains the element, it must throw an exception (rather than returning `false`). This preserves the invariant that a collection always contains the specified element after this call returns. Implementation Specification This implementation always throws an `UnsupportedOperationException`. Parameters e:E element whose presence in this collection is to be ensured Returns:boolean `true` if this collection changed as a result of the call Exceptions UnsupportedOperationException: if the `add` operation is not supported by this collection ClassCastException: if the class of the specified element prevents it from being added to this collection NullPointerException: if the specified element is null and this collection does not permit null elements IllegalArgumentException: if some property of the element prevents it from being added to this collection IllegalStateException: if the element cannot be added at this time due to insertion restrictions

public boolean add(E e)

Ensures that this collection contains the specified element (optional operation). Returns true if this collection changed as a result of the call. (Returns false if this collection does not permit duplicates and already contains the specified element.)

Collections that support this operation may place limitations on what elements may be added to this collection. In particular, some collections will refuse to add null elements, and others will impose restrictions on the type of elements that may be added. Collection classes should clearly specify in their documentation any restrictions on what elements may be added.

If a collection refuses to add a particular element for any reason other than that it already contains the element, it must throw an exception (rather than returning false). This preserves the invariant that a collection always contains the specified element after this call returns.

Implementation Specification

This implementation always throws an UnsupportedOperationException.

Parameters

e:E: element whose presence in this collection is to be ensured

Returns:boolean

true if this collection changed as a result of the call

Exceptions

UnsupportedOperationException:: if the add operation is not supported by this collection
ClassCastException:: if the class of the specified element prevents it from being added to this collection
NullPointerException:: if the specified element is null and this collection does not permit null elements
IllegalArgumentException:: if some property of the element prevents it from being added to this collection
IllegalStateException:: if the element cannot be added at this time due to insertion restrictions

addAll back to summary

addAll	back to summary
public boolean addAll(Collection<? extends E> c) Implements java.util.Collection.addAll. Doc from java.util.Collection.addAll. Adds all of the elements in the specified collection to this collection (optional operation). The behavior of this operation is undefined if the specified collection is modified while the operation is in progress. (This implies that the behavior of this call is undefined if the specified collection is this collection, and this collection is nonempty.) If the specified collection has a defined encounter order, processing of its elements generally occurs in that order. Implementation Specification This implementation iterates over the specified collection, and adds each object returned by the iterator to this collection, in turn. Note that this implementation will throw an `UnsupportedOperationException` unless `add` is overridden (assuming the specified collection is non-empty). Parameters c:Collection<? extends E> collection containing elements to be added to this collection Returns:boolean `true` if this collection changed as a result of the call Exceptions UnsupportedOperationException: if the `addAll` operation is not supported by this collection ClassCastException: if the class of an element of the specified collection prevents it from being added to this collection NullPointerException: if the specified collection contains a null element and this collection does not permit null elements, or if the specified collection is null IllegalArgumentException: if some property of an element of the specified collection prevents it from being added to this collection IllegalStateException: if not all the elements can be added at this time due to insertion restrictions See Also `add(Object)`

public boolean addAll(Collection<? extends E> c)

Implements java.util.Collection.addAll.

Doc from java.util.Collection.addAll.

Adds all of the elements in the specified collection to this collection (optional operation). The behavior of this operation is undefined if the specified collection is modified while the operation is in progress. (This implies that the behavior of this call is undefined if the specified collection is this collection, and this collection is nonempty.) If the specified collection has a defined encounter order, processing of its elements generally occurs in that order.

Implementation Specification

This implementation iterates over the specified collection, and adds each object returned by the iterator to this collection, in turn.

Note that this implementation will throw an UnsupportedOperationException unless add is overridden (assuming the specified collection is non-empty).

Parameters

c:Collection<? extends E>: collection containing elements to be added to this collection

Returns:boolean

true if this collection changed as a result of the call

Exceptions

UnsupportedOperationException:: if the addAll operation is not supported by this collection
ClassCastException:: if the class of an element of the specified collection prevents it from being added to this collection
NullPointerException:: if the specified collection contains a null element and this collection does not permit null elements, or if the specified collection is null
IllegalArgumentException:: if some property of an element of the specified collection prevents it from being added to this collection
IllegalStateException:: if not all the elements can be added at this time due to insertion restrictions

See Also

add(Object)

clear back to summary

clear	back to summary
public void clear() Implements java.util.Collection.clear. Doc from java.util.Collection.clear. Removes all of the elements from this collection (optional operation). The collection will be empty after this method returns. Implementation Specification This implementation iterates over this collection, removing each element using the `Iterator.remove` operation. Most implementations will probably choose to override this method for efficiency. Note that this implementation will throw an `UnsupportedOperationException` if the iterator returned by this collection's `iterator` method does not implement the `remove` method and this collection is non-empty. Exceptions UnsupportedOperationException: if the `clear` operation is not supported by this collection

public void clear()

Implements java.util.Collection.clear.

Doc from java.util.Collection.clear.

Removes all of the elements from this collection (optional operation). The collection will be empty after this method returns.

Implementation Specification

This implementation iterates over this collection, removing each element using the Iterator.remove operation. Most implementations will probably choose to override this method for efficiency.

Note that this implementation will throw an UnsupportedOperationException if the iterator returned by this collection's iterator method does not implement the remove method and this collection is non-empty.

Exceptions

UnsupportedOperationException:: if the clear operation is not supported by this collection

contains back to summary

contains	back to summary
public boolean contains(Object o) Implements java.util.Collection.contains. Doc from java.util.Collection.contains. Returns `true` if this collection contains the specified element. More formally, returns `true` if and only if this collection contains at least one element `e` such that `Objects.equals(o, e)`. Implementation Specification This implementation iterates over the elements in the collection, checking each element in turn for equality with the specified element. Parameters o:Object element whose presence in this collection is to be tested Returns:boolean `true` if this collection contains the specified element Exceptions ClassCastException: if the type of the specified element is incompatible with this collection (optional) NullPointerException: if the specified element is null and this collection does not permit null elements (optional)

public boolean contains(Object o)

Implements java.util.Collection.contains.

Doc from java.util.Collection.contains.

Returns true if this collection contains the specified element. More formally, returns true if and only if this collection contains at least one element e such that Objects.equals(o, e).

Implementation Specification

This implementation iterates over the elements in the collection, checking each element in turn for equality with the specified element.

Parameters

o:Object: element whose presence in this collection is to be tested

Returns:boolean

true if this collection contains the specified element

Exceptions

ClassCastException:: if the type of the specified element is incompatible with this collection (optional)
NullPointerException:: if the specified element is null and this collection does not permit null elements (optional)

containsAll back to summary

containsAll	back to summary
public boolean containsAll(Collection<?> c) Implements java.util.Collection.containsAll. Doc from java.util.Collection.containsAll. Returns `true` if this collection contains all of the elements in the specified collection. Implementation Specification This implementation iterates over the specified collection, checking each element returned by the iterator in turn to see if it's contained in this collection. If all elements are so contained `true` is returned, otherwise `false`. Parameters c:Collection<?> collection to be checked for containment in this collection Returns:boolean `true` if this collection contains all of the elements in the specified collection Exceptions ClassCastException: if the types of one or more elements in the specified collection are incompatible with this collection (optional) NullPointerException: if the specified collection contains one or more null elements and this collection does not permit null elements (optional) or if the specified collection is null. See Also `contains(Object)`

public boolean containsAll(Collection<?> c)

Implements java.util.Collection.containsAll.

Doc from java.util.Collection.containsAll.

Returns true if this collection contains all of the elements in the specified collection.

Implementation Specification

This implementation iterates over the specified collection, checking each element returned by the iterator in turn to see if it's contained in this collection. If all elements are so contained true is returned, otherwise false.

Parameters

c:Collection<?>: collection to be checked for containment in this collection

Returns:boolean

true if this collection contains all of the elements in the specified collection

Exceptions

ClassCastException:: if the types of one or more elements in the specified collection are incompatible with this collection (optional)
NullPointerException:: if the specified collection contains one or more null elements and this collection does not permit null elements (optional) or if the specified collection is null.

See Also

contains(Object)

finishToArray	back to summary
private static <T> T[] finishToArray(T[] r, Iterator<?> it) Reallocates the array being used within toArray when the iterator returned more elements than expected, and finishes filling it from the iterator. Parameters r:T[] the array, replete with previously stored elements it:Iterator<?> the in-progress iterator over this collection Returns:T[] array containing the elements in the given array, plus any further elements returned by the iterator, trimmed to size Annotations @SuppressWarnings:unchecked

finishToArray

back to summary

private static <T> T[] finishToArray(T[] r, Iterator<?> it)

Reallocates the array being used within toArray when the iterator returned more elements than expected, and finishes filling it from the iterator.

Parameters

r:T[]: the array, replete with previously stored elements
it:Iterator<?>: the in-progress iterator over this collection

Returns:T[]

array containing the elements in the given array, plus any further elements returned by the iterator, trimmed to size

Annotations

@SuppressWarnings:unchecked

isEmpty back to summary

isEmpty	back to summary
public boolean isEmpty() Implements java.util.Collection.isEmpty. Doc from java.util.Collection.isEmpty. Returns `true` if this collection contains no elements. Implementation Specification This implementation returns `size() == 0`. Returns:boolean `true` if this collection contains no elements

public boolean isEmpty()

Implements java.util.Collection.isEmpty.

Doc from java.util.Collection.isEmpty.

Returns true if this collection contains no elements.

Implementation Specification

This implementation returns size() == 0.

Returns:boolean: true if this collection contains no elements

iterator	back to summary
public abstract Iterator<E> iterator() Redeclares java.util.Collection.iterator. Returns an iterator over the elements contained in this collection. Returns:Iterator<E> an iterator over the elements contained in this collection

iterator

back to summary

public abstract Iterator<E> iterator()

Redeclares java.util.Collection.iterator.

Returns an iterator over the elements contained in this collection.

Returns:Iterator<E>: an iterator over the elements contained in this collection

remove back to summary

remove	back to summary
public boolean remove(Object o) Implements java.util.Collection.remove. Doc from java.util.Collection.remove. Removes a single instance of the specified element from this collection, if it is present (optional operation). More formally, removes an element `e` such that `Objects.equals(o, e)`, if this collection contains one or more such elements. Returns `true` if this collection contained the specified element (or equivalently, if this collection changed as a result of the call). Implementation Specification This implementation iterates over the collection looking for the specified element. If it finds the element, it removes the element from the collection using the iterator's remove method. Note that this implementation throws an `UnsupportedOperationException` if the iterator returned by this collection's iterator method does not implement the `remove` method and this collection contains the specified object. Parameters o:Object element to be removed from this collection, if present Returns:boolean `true` if an element was removed as a result of this call Exceptions UnsupportedOperationException: if the `remove` operation is not supported by this collection ClassCastException: if the type of the specified element is incompatible with this collection (optional) NullPointerException: if the specified element is null and this collection does not permit null elements (optional)

public boolean remove(Object o)

Implements java.util.Collection.remove.

Doc from java.util.Collection.remove.

Removes a single instance of the specified element from this collection, if it is present (optional operation). More formally, removes an element e such that Objects.equals(o, e), if this collection contains one or more such elements. Returns true if this collection contained the specified element (or equivalently, if this collection changed as a result of the call).

Implementation Specification

This implementation iterates over the collection looking for the specified element. If it finds the element, it removes the element from the collection using the iterator's remove method.

Note that this implementation throws an UnsupportedOperationException if the iterator returned by this collection's iterator method does not implement the remove method and this collection contains the specified object.

Parameters

o:Object: element to be removed from this collection, if present

Returns:boolean

true if an element was removed as a result of this call

Exceptions

UnsupportedOperationException:: if the remove operation is not supported by this collection
ClassCastException:: if the type of the specified element is incompatible with this collection (optional)
NullPointerException:: if the specified element is null and this collection does not permit null elements (optional)

removeAll back to summary

removeAll	back to summary
public boolean removeAll(Collection<?> c) Implements java.util.Collection.removeAll. Doc from java.util.Collection.removeAll. Removes all of this collection's elements that are also contained in the specified collection (optional operation). After this call returns, this collection will contain no elements in common with the specified collection. Implementation Specification This implementation iterates over this collection, checking each element returned by the iterator in turn to see if it's contained in the specified collection. If it's so contained, it's removed from this collection with the iterator's `remove` method. Note that this implementation will throw an `UnsupportedOperationException` if the iterator returned by the `iterator` method does not implement the `remove` method and this collection contains one or more elements in common with the specified collection. Parameters c:Collection<?> collection containing elements to be removed from this collection Returns:boolean `true` if this collection changed as a result of the call Exceptions UnsupportedOperationException: if the `removeAll` operation is not supported by this collection ClassCastException: if the types of one or more elements in this collection are incompatible with the specified collection (optional) NullPointerException: if this collection contains one or more null elements and the specified collection does not support null elements (optional) or if the specified collection is null See Also `remove(Object)`, `contains(Object)`

public boolean removeAll(Collection<?> c)

Implements java.util.Collection.removeAll.

Doc from java.util.Collection.removeAll.

Removes all of this collection's elements that are also contained in the specified collection (optional operation). After this call returns, this collection will contain no elements in common with the specified collection.

Implementation Specification

This implementation iterates over this collection, checking each element returned by the iterator in turn to see if it's contained in the specified collection. If it's so contained, it's removed from this collection with the iterator's remove method.

Note that this implementation will throw an UnsupportedOperationException if the iterator returned by the iterator method does not implement the remove method and this collection contains one or more elements in common with the specified collection.

Parameters

c:Collection<?>: collection containing elements to be removed from this collection

Returns:boolean

true if this collection changed as a result of the call

Exceptions

UnsupportedOperationException:: if the removeAll operation is not supported by this collection
ClassCastException:: if the types of one or more elements in this collection are incompatible with the specified collection (optional)
NullPointerException:: if this collection contains one or more null elements and the specified collection does not support null elements (optional) or if the specified collection is null

See Also

remove(Object), contains(Object)

retainAll back to summary

retainAll	back to summary
public boolean retainAll(Collection<?> c) Implements java.util.Collection.retainAll. Doc from java.util.Collection.retainAll. Retains only the elements in this collection that are contained in the specified collection (optional operation). In other words, removes from this collection all of its elements that are not contained in the specified collection. Implementation Specification This implementation iterates over this collection, checking each element returned by the iterator in turn to see if it's contained in the specified collection. If it's not so contained, it's removed from this collection with the iterator's `remove` method. Note that this implementation will throw an `UnsupportedOperationException` if the iterator returned by the `iterator` method does not implement the `remove` method and this collection contains one or more elements not present in the specified collection. Parameters c:Collection<?> collection containing elements to be retained in this collection Returns:boolean `true` if this collection changed as a result of the call Exceptions UnsupportedOperationException: if the `retainAll` operation is not supported by this collection ClassCastException: if the types of one or more elements in this collection are incompatible with the specified collection (optional) NullPointerException: if this collection contains one or more null elements and the specified collection does not permit null elements (optional) or if the specified collection is null See Also `remove(Object)`, `contains(Object)`

public boolean retainAll(Collection<?> c)

Implements java.util.Collection.retainAll.

Doc from java.util.Collection.retainAll.

Retains only the elements in this collection that are contained in the specified collection (optional operation). In other words, removes from this collection all of its elements that are not contained in the specified collection.

Implementation Specification

This implementation iterates over this collection, checking each element returned by the iterator in turn to see if it's contained in the specified collection. If it's not so contained, it's removed from this collection with the iterator's remove method.

Parameters

c:Collection<?>: collection containing elements to be retained in this collection

Returns:boolean

true if this collection changed as a result of the call

Exceptions

UnsupportedOperationException:: if the retainAll operation is not supported by this collection
ClassCastException:: if the types of one or more elements in this collection are incompatible with the specified collection (optional)
NullPointerException:: if this collection contains one or more null elements and the specified collection does not permit null elements (optional) or if the specified collection is null

See Also

remove(Object), contains(Object)

size back to summary

size	back to summary
public abstract int size() Redeclares java.util.Collection.size. Doc from java.util.Collection.size. Returns the number of elements in this collection. If this collection contains more than `Integer.MAX_VALUE` elements, returns `Integer.MAX_VALUE`. Returns:int the number of elements in this collection

public abstract int size()

Redeclares java.util.Collection.size.

Doc from java.util.Collection.size.

Returns the number of elements in this collection. If this collection contains more than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE.

Returns:int: the number of elements in this collection

toArray back to summary

toArray	back to summary
public Object[] toArray() Implements java.util.Collection.toArray. Doc from java.util.Collection.toArray. Returns an array containing all of the elements in this collection. If this collection makes any guarantees as to what order its elements are returned by its iterator, this method must return the elements in the same order. The returned array's runtime component type is `Object`. The returned array will be "safe" in that no references to it are maintained by this collection. (In other words, this method must allocate a new array even if this collection is backed by an array). The caller is thus free to modify the returned array. Implementation Specification This implementation returns an array containing all the elements returned by this collection's iterator, in the same order, stored in consecutive elements of the array, starting with index `0`. The length of the returned array is equal to the number of elements returned by the iterator, even if the size of this collection changes during iteration, as might happen if the collection permits concurrent modification during iteration. The `size` method is called only as an optimization hint; the correct result is returned even if the iterator returns a different number of elements. This method is equivalent to: `List<E> list = new ArrayList<E>(size()); for (E e : this) list.add(e); return list.toArray();` Returns:Object[] an array, whose runtime component type is `Object`, containing all of the elements in this collection

public Object[] toArray()

Implements java.util.Collection.toArray.

Doc from java.util.Collection.toArray.

Returns an array containing all of the elements in this collection. If this collection makes any guarantees as to what order its elements are returned by its iterator, this method must return the elements in the same order. The returned array's runtime component type is Object.

The returned array will be "safe" in that no references to it are maintained by this collection. (In other words, this method must allocate a new array even if this collection is backed by an array). The caller is thus free to modify the returned array.

Implementation Specification

This implementation returns an array containing all the elements returned by this collection's iterator, in the same order, stored in consecutive elements of the array, starting with index 0. The length of the returned array is equal to the number of elements returned by the iterator, even if the size of this collection changes during iteration, as might happen if the collection permits concurrent modification during iteration. The size method is called only as an optimization hint; the correct result is returned even if the iterator returns a different number of elements.

This method is equivalent to:

 List<E> list = new ArrayList<E>(size());
for (E e : this)
    list.add(e);
return list.toArray();

Returns:Object[]: an array, whose runtime component type is Object, containing all of the elements in this collection

toArray back to summary

toArray	back to summary
public <T> T[] toArray(T[] a) Implements java.util.Collection.toArray. Doc from java.util.Collection.toArray. Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array. If the collection fits in the specified array, it is returned therein. Otherwise, a new array is allocated with the runtime type of the specified array and the size of this collection. If this collection fits in the specified array with room to spare (i.e., the array has more elements than this collection), the element in the array immediately following the end of the collection is set to `null`. (This is useful in determining the length of this collection only if the caller knows that this collection does not contain any `null` elements.) If this collection makes any guarantees as to what order its elements are returned by its iterator, this method must return the elements in the same order. Implementation Specification This implementation returns an array containing all the elements returned by this collection's iterator in the same order, stored in consecutive elements of the array, starting with index `0`. If the number of elements returned by the iterator is too large to fit into the specified array, then the elements are returned in a newly allocated array with length equal to the number of elements returned by the iterator, even if the size of this collection changes during iteration, as might happen if the collection permits concurrent modification during iteration. The `size` method is called only as an optimization hint; the correct result is returned even if the iterator returns a different number of elements. This method is equivalent to: `List<E> list = new ArrayList<E>(size()); for (E e : this) list.add(e); return list.toArray(a);` Parameters <T> the component type of the array to contain the collection a:T[] the array into which the elements of this collection are to be stored, if it is big enough; otherwise, a new array of the same runtime type is allocated for this purpose. Returns:T[] an array containing all of the elements in this collection Annotations @SuppressWarnings:unchecked Exceptions ArrayStoreException: if the runtime type of any element in this collection is not assignable to the runtime component type of the specified array NullPointerException: if the specified array is null

public <T> T[] toArray(T[] a)

Implements java.util.Collection.toArray.

Doc from java.util.Collection.toArray.

Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array. If the collection fits in the specified array, it is returned therein. Otherwise, a new array is allocated with the runtime type of the specified array and the size of this collection.

If this collection fits in the specified array with room to spare (i.e., the array has more elements than this collection), the element in the array immediately following the end of the collection is set to null. (This is useful in determining the length of this collection only if the caller knows that this collection does not contain any null elements.)

If this collection makes any guarantees as to what order its elements are returned by its iterator, this method must return the elements in the same order.

Implementation Specification

This implementation returns an array containing all the elements returned by this collection's iterator in the same order, stored in consecutive elements of the array, starting with index 0. If the number of elements returned by the iterator is too large to fit into the specified array, then the elements are returned in a newly allocated array with length equal to the number of elements returned by the iterator, even if the size of this collection changes during iteration, as might happen if the collection permits concurrent modification during iteration. The size method is called only as an optimization hint; the correct result is returned even if the iterator returns a different number of elements.

This method is equivalent to:

 List<E> list = new ArrayList<E>(size());
for (E e : this)
    list.add(e);
return list.toArray(a);

Parameters

<T>: the component type of the array to contain the collection
a:T[]: the array into which the elements of this collection are to be stored, if it is big enough; otherwise, a new array of the same runtime type is allocated for this purpose.

Returns:T[]

an array containing all of the elements in this collection

Annotations

@SuppressWarnings:unchecked

Exceptions

ArrayStoreException:: if the runtime type of any element in this collection is not assignable to the runtime component type of the specified array
NullPointerException:: if the specified array is null

toString back to summary

toString	back to summary
public String toString() Overrides java.lang.Object.toString. Returns a string representation of this collection. The string representation consists of a list of the collection's elements in the order they are returned by its iterator, enclosed in square brackets (`"[]"`). Adjacent elements are separated by the characters `", "` (comma and space). Elements are converted to strings as by `String#valueOf(Object)`. Returns:String a string representation of this collection

public String toString()

Overrides java.lang.Object.toString.

Returns a string representation of this collection. The string representation consists of a list of the collection's elements in the order they are returned by its iterator, enclosed in square brackets ("[]"). Adjacent elements are separated by the characters ", " (comma and space). Elements are converted to strings as by String#valueOf(Object).

Returns:String: a string representation of this collection

public abstract Class AbstractCollection<E>

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Constructor Detail

Method Detail