OpenJDK 1.23 · java.lang.Float · APIdia, the JavaDoc alternative

Modifier and Type	Field and Description
public static final int	BYTES The number of bytes used to represent a `float` value.
public static final int	MAX_EXPONENT Maximum exponent a finite `float` variable may have.
public static final float	MAX_VALUE A constant holding the largest positive finite value of type `float`, (2-2^-23)·2¹²⁷.
public static final int	MIN_EXPONENT Minimum exponent a normalized `float` variable may have.
public static final float	MIN_NORMAL A constant holding the smallest positive normal value of type `float`, 2^-126.
public static final float	MIN_VALUE A constant holding the smallest positive nonzero value of type `float`, 2^-149.
public static final float	NaN A constant holding a Not-a-Number (NaN) value of type `float`.
public static final float	NEGATIVE_INFINITY A constant holding the negative infinity of type `float`.
public static final float	POSITIVE_INFINITY A constant holding the positive infinity of type `float`.
public static final int	PRECISION The number of bits in the significand of a `float` value.
private static final long	serialVersionUID Hides java.lang.Number.serialVersionUID. use serialVersionUID from JDK 1.0.2 for interoperability
public static final int	SIZE The number of bits used to represent a `float` value.
public static final Class<Float>	TYPE The `Class` instance representing the primitive type `float`.
private final float	value The value of the Float.

Access	Constructor and Description
public	Float(float the value to be represented by the `Float`. value) Deprecated for removal since 9. It is rarely appropriate to use this constructor. Constructs a newly allocated `Float` object that represents the primitive `float` argument.
public	Float(double the value to be represented by the `Float`. value) Deprecated for removal since 9. It is rarely appropriate to use this constructor. Constructs a newly allocated `Float` object that represents the argument converted to type `float`.
public	Float(String a string to be converted to a `Float`. s) Deprecated for removal since 9. It is rarely appropriate to use this constructor. Constructs a newly allocated `Float` object that represents the floating-point value of type `float` represented by the string.

Method Summary

Modifier and Type	Method and Description
public byte	Returns: the `float` value represented by this object converted to type `byte` byteValue() Overrides java.lang.Number.byteValue. Returns the value of this `Float` as a `byte` after a narrowing primitive conversion.
public static int	Returns: the value `0` if `f1` is numerically equal to `f2`; a value less than `0` if `f1` is numerically less than `f2`; and a value greater than `0` if `f1` is numerically greater than `f2`. compare(float the first `float` to compare. f1, float the second `float` to compare. f2) Compares the two specified `float` values.
public int	Returns: the value `0` if `anotherFloat` is numerically equal to this `Float`; a value less than `0` if this `Float` is numerically less than `anotherFloat`; and a value greater than `0` if this `Float` is numerically greater than `anotherFloat`. compareTo(Float the `Float` to be compared. anotherFloat) Implements java.lang.Comparable.compareTo. Compares two `Float` objects numerically.
public Optional<Float>	Returns: an `Optional` describing the Float instance describeConstable() Implements java.lang.constant.Constable.describeConstable. Returns an `Optional` containing the nominal descriptor for this instance, which is the instance itself.
public double	Returns: the `float` value represented by this object converted to type `double` doubleValue() Implements abstract java.lang.Number.doubleValue. Returns the value of this `Float` as a `double` after a widening primitive conversion.
public boolean	Returns: `true` if the objects are the same; `false` otherwise. equals(Object the object to be compared obj) Overrides java.lang.Object.equals. Compares this object against the specified object.
public static float	Returns: the `float` value closest to the numerical value of the argument, a floating-point binary16 value encoded in a `short` float16ToFloat(short the binary16 value to convert to `float` floatBinary16) Returns the `float` value closest to the numerical value of the argument, a floating-point binary16 value encoded in a `short`.
public static short	Returns: the floating-point binary16 value, encoded in a `short`, closest in value to the argument floatToFloat16(float the `float` value to convert to binary16 f) Returns the floating-point binary16 value, encoded in a `short`, closest in value to the argument.
public static int	Returns: the bits that represent the floating-point number. floatToIntBits(float a floating-point number. value) Returns a representation of the specified floating-point value according to the IEEE 754 floating-point "single format" bit layout.
public static native int	Returns: the bits that represent the floating-point number. floatToRawIntBits(float a floating-point number. value) Returns a representation of the specified floating-point value according to the IEEE 754 floating-point "single format" bit layout, preserving Not-a-Number (NaN) values.
public float	Returns: the `float` value represented by this object floatValue() Implements abstract java.lang.Number.floatValue. Returns the `float` value of this `Float` object.
public int	Returns: a hash code value for this object. hashCode() Overrides java.lang.Object.hashCode. Returns a hash code for this `Float` object.
public static int	Returns: a hash code value for a `float` value. hashCode(float the value to hash value) Returns a hash code for a `float` value; compatible with `Float.hashCode()`.
public static native float	Returns: the `float` floating-point value with the same bit pattern. intBitsToFloat(int an integer. bits) Returns the `float` value corresponding to a given bit representation.
public int	Returns: the `float` value represented by this object converted to type `int` intValue() Implements abstract java.lang.Number.intValue. Returns the value of this `Float` as an `int` after a narrowing primitive conversion.
public static boolean	Returns: `true` if the argument is a finite floating-point value, `false` otherwise. isFinite(float the `float` value to be tested f) Returns `true` if the argument is a finite floating-point value; returns `false` otherwise (for NaN and infinity arguments).
public static boolean	Returns: `true` if the argument is positive infinity or negative infinity; `false` otherwise. isInfinite(float the value to be tested. v) Returns `true` if the specified number is infinitely large in magnitude, `false` otherwise.
public boolean	Returns: `true` if the value represented by this object is positive infinity or negative infinity; `false` otherwise. isInfinite() Returns `true` if this `Float` value is infinitely large in magnitude, `false` otherwise.
public static boolean	Returns: `true` if the argument is NaN; `false` otherwise. isNaN(float the value to be tested. v) Returns `true` if the specified number is a Not-a-Number (NaN) value, `false` otherwise.
public boolean	Returns: `true` if the value represented by this object is NaN; `false` otherwise. isNaN() Returns `true` if this `Float` value is a Not-a-Number (NaN), `false` otherwise.
public long	Returns: the `float` value represented by this object converted to type `long` longValue() Implements abstract java.lang.Number.longValue. Returns value of this `Float` as a `long` after a narrowing primitive conversion.
public static float	Returns: the greater of `a` and `b` max(float the first operand a, float the second operand b) Returns the greater of two `float` values as if by calling `Math.max`.
public static float	Returns: the smaller of `a` and `b` min(float the first operand a, float the second operand b) Returns the smaller of two `float` values as if by calling `Math.min`.
public static float	Returns: the `float` value represented by the string argument. parseFloat(String the string to be parsed. s) Returns a new `float` initialized to the value represented by the specified `String`, as performed by the `valueOf` method of class `Float`.
public Float	Returns: the Float instance resolveConstantDesc(MethodHandles.Lookup ignored lookup) Implements java.lang.constant.ConstantDesc.resolveConstantDesc. Resolves this instance as a `ConstantDesc`, the result of which is the instance itself.
public short	Returns: the `float` value represented by this object converted to type `short` shortValue() Overrides java.lang.Number.shortValue. Returns the value of this `Float` as a `short` after a narrowing primitive conversion.
public static float	Returns: the sum of `a` and `b` sum(float the first operand a, float the second operand b) Adds two `float` values together as per the + operator.
public static String	Returns: a hex string representation of the argument. toHexString(float the `float` to be converted. f) Returns a hexadecimal string representation of the `float` argument.
public static String	Returns: a string representation of the argument. toString(float the `float` to be converted. f) Returns a string representation of the `float` argument.
public String	Returns: a `String` representation of this object. toString() Overrides java.lang.Object.toString. Returns a string representation of this `Float` object.
public static Float	Returns: a `Float` object holding the value represented by the `String` argument. valueOf(String the string to be parsed. s) Returns a `Float` object holding the `float` value represented by the argument string `s`.
public static Float	Returns: a `Float` instance representing `f`. valueOf(float a float value. f) Returns a `Float` instance representing the specified `float` value.

BYTES	back to summary
public static final int BYTES The number of bytes used to represent a `float` value. Since 1.8

MAX_EXPONENT	back to summary
public static final int MAX_EXPONENT Maximum exponent a finite `float` variable may have. It is equal to the value returned by `Math.getExponent(Float.MAX_VALUE)`. Since 1.6

MAX_VALUE	back to summary
public static final float MAX_VALUE A constant holding the largest positive finite value of type `float`, (2-2^-23)·2¹²⁷. It is equal to the hexadecimal floating-point literal `0x1.fffffeP+127f` and also equal to `Float.intBitsToFloat(0x7f7fffff)`.

MIN_EXPONENT	back to summary
public static final int MIN_EXPONENT Minimum exponent a normalized `float` variable may have. It is equal to the value returned by `Math.getExponent(Float.MIN_NORMAL)`. Since 1.6

MIN_NORMAL	back to summary
public static final float MIN_NORMAL A constant holding the smallest positive normal value of type `float`, 2^-126. It is equal to the hexadecimal floating-point literal `0x1.0p-126f` and also equal to `Float.intBitsToFloat(0x00800000)`. Since 1.6

MIN_VALUE	back to summary
public static final float MIN_VALUE A constant holding the smallest positive nonzero value of type `float`, 2^-149. It is equal to the hexadecimal floating-point literal `0x0.000002P-126f` and also equal to `Float.intBitsToFloat(0x1)`.

NaN	back to summary
public static final float NaN A constant holding a Not-a-Number (NaN) value of type `float`. It is equivalent to the value returned by `Float.intBitsToFloat(0x7fc00000)`.

NEGATIVE_INFINITY	back to summary
public static final float NEGATIVE_INFINITY A constant holding the negative infinity of type `float`. It is equal to the value returned by `Float.intBitsToFloat(0xff800000)`.

POSITIVE_INFINITY	back to summary
public static final float POSITIVE_INFINITY A constant holding the positive infinity of type `float`. It is equal to the value returned by `Float.intBitsToFloat(0x7f800000)`.

PRECISION	back to summary
public static final int PRECISION The number of bits in the significand of a `float` value. This is the parameter N in section 4.2.3 of The Java Language Specification. Since 19

serialVersionUID	back to summary
private static final long serialVersionUID Hides java.lang.Number.serialVersionUID. use serialVersionUID from JDK 1.0.2 for interoperability Annotations @Serial

SIZE	back to summary
public static final int SIZE The number of bits used to represent a `float` value. Since 1.5

TYPE	back to summary
public static final Class<Float> TYPE The `Class` instance representing the primitive type `float`. Annotations @SuppressWarnings:unchecked Since 1.1

value	back to summary
private final float value The value of the Float.

Float	back to summary
public Float(float value) Deprecated for removal since 9. It is rarely appropriate to use this constructor. The static factory `valueOf(float)` is generally a better choice, as it is likely to yield significantly better space and time performance. Constructs a newly allocated `Float` object that represents the primitive `float` argument. Parameters value:float the value to be represented by the `Float`. Annotations @Deprecated since:9 forRemoval:true

Float	back to summary
public Float(double value) Deprecated for removal since 9. It is rarely appropriate to use this constructor. Instead, use the static factory method `valueOf(float)` method as follows: `Float.valueOf((float)value)`. Constructs a newly allocated `Float` object that represents the argument converted to type `float`. Parameters value:double the value to be represented by the `Float`. Annotations @Deprecated since:9 forRemoval:true

Float	back to summary
public Float(String s) throws NumberFormatException Deprecated for removal since 9. It is rarely appropriate to use this constructor. Use `parseFloat(String)` to convert a string to a `float` primitive, or use `valueOf(String)` to convert a string to a `Float` object. Constructs a newly allocated `Float` object that represents the floating-point value of type `float` represented by the string. The string is converted to a `float` value as if by the `valueOf` method. Parameters s:String a string to be converted to a `Float`. Annotations @Deprecated since:9 forRemoval:true Exceptions NumberFormatException: if the string does not contain a parsable number.

Method Detail

byteValue back to summary

byteValue	back to summary
public byte byteValue() Overrides java.lang.Number.byteValue. Returns the value of this `Float` as a `byte` after a narrowing primitive conversion. Returns:byte the `float` value represented by this object converted to type `byte` Java Language Specification 5.1.3 Narrowing Primitive Conversion

public byte byteValue()

Overrides java.lang.Number.byteValue.

Returns the value of this Float as a byte after a narrowing primitive conversion.

Returns:byte: the float value represented by this object converted to type byte
Java Language Specification: 5.1.3 Narrowing Primitive Conversion

compare back to summary

compare	back to summary
public static int compare(float f1, float f2) Compares the two specified `float` values. The sign of the integer value returned is the same as that of the integer that would be returned by the call: Float.valueOf(f1).compareTo(Float.valueOf(f2)) Parameters f1:float the first `float` to compare. f2:float the second `float` to compare. Returns:int the value `0` if `f1` is numerically equal to `f2`; a value less than `0` if `f1` is numerically less than `f2`; and a value greater than `0` if `f1` is numerically greater than `f2`. Since 1.4

public static int compare(float f1, float f2)

Compares the two specified float values. The sign of the integer value returned is the same as that of the integer that would be returned by the call:

   Float.valueOf(f1).compareTo(Float.valueOf(f2))

Parameters

f1:float: the first float to compare.
f2:float: the second float to compare.

Returns:int

the value 0 if f1 is numerically equal to f2; a value less than 0 if f1 is numerically less than f2; and a value greater than 0 if f1 is numerically greater than f2.

Since

1.4

compareTo back to summary

compareTo	back to summary
public int compareTo(Float anotherFloat) Implements java.lang.Comparable.compareTo. Compares two `Float` objects numerically. This method imposes a total order on `Float` objects with two differences compared to the incomplete order defined by the Java language numerical comparison operators (`<, <=, ==, >=, >`) on `float` values. A NaN is unordered with respect to other values and unequal to itself under the comparison operators. This method chooses to define `Float.NaN` to be equal to itself and greater than all other `double` values (including `Float.POSITIVE_INFINITY`). Positive zero and negative zero compare equal numerically, but are distinct and distinguishable values. This method chooses to define positive zero (`+0.0f`), to be greater than negative zero (`-0.0f`). This ensures that the natural ordering of `Float` objects imposed by this method is consistent with equals; see this discussion for details of floating-point comparison and ordering. Parameters anotherFloat:Float the `Float` to be compared. Returns:int the value `0` if `anotherFloat` is numerically equal to this `Float`; a value less than `0` if this `Float` is numerically less than `anotherFloat`; and a value greater than `0` if this `Float` is numerically greater than `anotherFloat`. Since 1.2 Java Language Specification 15.20.1 Numerical Comparison Operators `<`, `<=`, `>`, and `>=`

public int compareTo(Float anotherFloat)

Implements java.lang.Comparable.compareTo.

Compares two Float objects numerically. This method imposes a total order on Float objects with two differences compared to the incomplete order defined by the Java language numerical comparison operators (<, <=, ==, >=, >) on float values.

A NaN is unordered with respect to other values and unequal to itself under the comparison operators. This method chooses to define Float.NaN to be equal to itself and greater than all other double values (including Float.POSITIVE_INFINITY).
Positive zero and negative zero compare equal numerically, but are distinct and distinguishable values. This method chooses to define positive zero (+0.0f), to be greater than negative zero (-0.0f).

This ensures that the natural ordering of Float objects imposed by this method is consistent with equals; see this discussion for details of floating-point comparison and ordering.

Parameters

anotherFloat:Float: the Float to be compared.

Returns:int

the value 0 if anotherFloat is numerically equal to this Float; a value less than 0 if this Float is numerically less than anotherFloat; and a value greater than 0 if this Float is numerically greater than anotherFloat.

Since

1.2

Java Language Specification

15.20.1 Numerical Comparison Operators <, <=, >, and >=

describeConstable back to summary

describeConstable	back to summary
public Optional<Float> describeConstable() Implements java.lang.constant.Constable.describeConstable. Returns an `Optional` containing the nominal descriptor for this instance, which is the instance itself. Returns:Optional<Float> an `Optional` describing the Float instance Annotations @Override Since 12

public Optional<Float> describeConstable()

Implements java.lang.constant.Constable.describeConstable.

Returns an Optional containing the nominal descriptor for this instance, which is the instance itself.

Returns:Optional<Float>

an Optional describing the Float instance

Annotations

@Override

Since

doubleValue back to summary

doubleValue	back to summary
public double doubleValue() Implements abstract java.lang.Number.doubleValue. Returns the value of this `Float` as a `double` after a widening primitive conversion. API Note This method corresponds to the convertFormat operation defined in IEEE 754. Returns:double the `float` value represented by this object converted to type `double` Java Language Specification 5.1.2 Widening Primitive Conversion

public double doubleValue()

Implements abstract java.lang.Number.doubleValue.

Returns the value of this Float as a double after a widening primitive conversion.

API Note

This method corresponds to the convertFormat operation defined in IEEE 754.

Returns:double: the float value represented by this object converted to type double
Java Language Specification: 5.1.2 Widening Primitive Conversion

equals back to summary

equals	back to summary
public boolean equals(Object obj) Overrides java.lang.Object.equals. Compares this object against the specified object. The result is `true` if and only if the argument is not `null` and is a `Float` object that represents a `float` with the same value as the `float` represented by this object. For this purpose, two `float` values are considered to be the same if and only if the method `floatToIntBits(float)` returns the identical `int` value when applied to each. API Note This method is defined in terms of `floatToIntBits(float)` rather than the `==` operator on `float` values since the `==` operator does not define an equivalence relation and to satisfy the equals contract an equivalence relation must be implemented; see this discussion for details of floating-point equality and equivalence. Parameters obj:Object the object to be compared Returns:boolean `true` if the objects are the same; `false` otherwise. Java Language Specification 15.21.1 Numerical Equality Operators == and != See Also `java.lang.Float#floatToIntBits(float)`

public boolean equals(Object obj)

Overrides java.lang.Object.equals.

Compares this object against the specified object. The result is true if and only if the argument is not null and is a Float object that represents a float with the same value as the float represented by this object. For this purpose, two float values are considered to be the same if and only if the method floatToIntBits(float) returns the identical int value when applied to each.

API Note

This method is defined in terms of floatToIntBits(float) rather than the == operator on float values since the == operator does not define an equivalence relation and to satisfy the equals contract an equivalence relation must be implemented; see this discussion for details of floating-point equality and equivalence.

Parameters

obj:Object: the object to be compared

Returns:boolean

true if the objects are the same; false otherwise.

Java Language Specification

15.21.1 Numerical Equality Operators == and !=

See Also

java.lang.Float#floatToIntBits(float)

float16ToFloat back to summary

float16ToFloat	back to summary
public static float float16ToFloat(short floatBinary16) Returns the `float` value closest to the numerical value of the argument, a floating-point binary16 value encoded in a `short`. The conversion is exact; all binary16 values can be exactly represented in `float`. Special cases: If the argument is zero, the result is a zero with the same sign as the argument. If the argument is infinite, the result is an infinity with the same sign as the argument. If the argument is a NaN, the result is a NaN. IEEE 754 binary16 format The IEEE 754 standard defines binary16 as a 16-bit format, along with the 32-bit binary32 format (corresponding to the `float` type) and the 64-bit binary64 format (corresponding to the `double` type). The binary16 format is similar to the other IEEE 754 formats, except smaller, having all the usual IEEE 754 values such as NaN, signed infinities, signed zeros, and subnormals. The parameters (JLS 4.2.3) for the binary16 format are N = 11 precision bits, K = 5 exponent bits, E_max = 15, and E_min = -14. API Note This method corresponds to the convertFormat operation defined in IEEE 754 from the binary16 format to the binary32 format. The operation of this method is analogous to a primitive widening conversion (JLS 5.1.2). Parameters floatBinary16:short the binary16 value to convert to `float` Returns:float the `float` value closest to the numerical value of the argument, a floating-point binary16 value encoded in a `short` Annotations @IntrinsicCandidate Since 20

public static float float16ToFloat(short floatBinary16)

Returns the float value closest to the numerical value of the argument, a floating-point binary16 value encoded in a short. The conversion is exact; all binary16 values can be exactly represented in float. Special cases:

If the argument is zero, the result is a zero with the same sign as the argument.
If the argument is infinite, the result is an infinity with the same sign as the argument.
If the argument is a NaN, the result is a NaN.

IEEE 754 binary16 format

The IEEE 754 standard defines binary16 as a 16-bit format, along with the 32-bit binary32 format (corresponding to the float type) and the 64-bit binary64 format (corresponding to the double type). The binary16 format is similar to the other IEEE 754 formats, except smaller, having all the usual IEEE 754 values such as NaN, signed infinities, signed zeros, and subnormals. The parameters (JLS 4.2.3) for the binary16 format are N = 11 precision bits, K = 5 exponent bits, E_max = 15, and E_min = -14.

API Note

This method corresponds to the convertFormat operation defined in IEEE 754 from the binary16 format to the binary32 format. The operation of this method is analogous to a primitive widening conversion (JLS 5.1.2).

Parameters

floatBinary16:short: the binary16 value to convert to float

Returns:float

the float value closest to the numerical value of the argument, a floating-point binary16 value encoded in a short

Annotations

@IntrinsicCandidate

Since

floatToFloat16 back to summary

floatToFloat16	back to summary
public static short floatToFloat16(float f) Returns the floating-point binary16 value, encoded in a `short`, closest in value to the argument. The conversion is computed under the round to nearest even rounding mode. Special cases: If the argument is zero, the result is a zero with the same sign as the argument. If the argument is infinite, the result is an infinity with the same sign as the argument. If the argument is a NaN, the result is a NaN. The binary16 format is discussed in more detail in the `float16ToFloat` method. API Note This method corresponds to the convertFormat operation defined in IEEE 754 from the binary32 format to the binary16 format. The operation of this method is analogous to a primitive narrowing conversion (JLS 5.1.3). Parameters f:float the `float` value to convert to binary16 Returns:short the floating-point binary16 value, encoded in a `short`, closest in value to the argument Annotations @IntrinsicCandidate Since 20

public static short floatToFloat16(float f)

Returns the floating-point binary16 value, encoded in a short, closest in value to the argument. The conversion is computed under the round to nearest even rounding mode. Special cases:

If the argument is zero, the result is a zero with the same sign as the argument.
If the argument is infinite, the result is an infinity with the same sign as the argument.
If the argument is a NaN, the result is a NaN.

The binary16 format is discussed in more detail in the float16ToFloat method.

API Note

This method corresponds to the convertFormat operation defined in IEEE 754 from the binary32 format to the binary16 format. The operation of this method is analogous to a primitive narrowing conversion (JLS 5.1.3).

Parameters

f:float: the float value to convert to binary16

Returns:short

the floating-point binary16 value, encoded in a short, closest in value to the argument

Annotations

@IntrinsicCandidate

Since

floatToIntBits back to summary

floatToIntBits	back to summary
public static int floatToIntBits(float value) Returns a representation of the specified floating-point value according to the IEEE 754 floating-point "single format" bit layout. Bit 31 (the bit that is selected by the mask `0x80000000`) represents the sign of the floating-point number. Bits 30-23 (the bits that are selected by the mask `0x7f800000`) represent the exponent. Bits 22-0 (the bits that are selected by the mask `0x007fffff`) represent the significand (sometimes called the mantissa) of the floating-point number. If the argument is positive infinity, the result is `0x7f800000`. If the argument is negative infinity, the result is `0xff800000`. If the argument is NaN, the result is `0x7fc00000`. In all cases, the result is an integer that, when given to the `intBitsToFloat(int)` method, will produce a floating-point value the same as the argument to `floatToIntBits` (except all NaN values are collapsed to a single "canonical" NaN value). Parameters value:float a floating-point number. Returns:int the bits that represent the floating-point number. Annotations @IntrinsicCandidate

public static int floatToIntBits(float value)

Returns a representation of the specified floating-point value according to the IEEE 754 floating-point "single format" bit layout.

Bit 31 (the bit that is selected by the mask 0x80000000) represents the sign of the floating-point number. Bits 30-23 (the bits that are selected by the mask 0x7f800000) represent the exponent. Bits 22-0 (the bits that are selected by the mask 0x007fffff) represent the significand (sometimes called the mantissa) of the floating-point number.

If the argument is positive infinity, the result is 0x7f800000.

If the argument is negative infinity, the result is 0xff800000.

If the argument is NaN, the result is 0x7fc00000.

In all cases, the result is an integer that, when given to the intBitsToFloat(int) method, will produce a floating-point value the same as the argument to floatToIntBits (except all NaN values are collapsed to a single "canonical" NaN value).

Parameters

value:float: a floating-point number.

Returns:int

the bits that represent the floating-point number.

Annotations

@IntrinsicCandidate

floatToRawIntBits back to summary

floatToRawIntBits	back to summary
public static native int floatToRawIntBits(float value) Returns a representation of the specified floating-point value according to the IEEE 754 floating-point "single format" bit layout, preserving Not-a-Number (NaN) values. Bit 31 (the bit that is selected by the mask `0x80000000`) represents the sign of the floating-point number. Bits 30-23 (the bits that are selected by the mask `0x7f800000`) represent the exponent. Bits 22-0 (the bits that are selected by the mask `0x007fffff`) represent the significand (sometimes called the mantissa) of the floating-point number. If the argument is positive infinity, the result is `0x7f800000`. If the argument is negative infinity, the result is `0xff800000`. If the argument is NaN, the result is the integer representing the actual NaN value. Unlike the `floatToIntBits` method, `floatToRawIntBits` does not collapse all the bit patterns encoding a NaN to a single "canonical" NaN value. In all cases, the result is an integer that, when given to the `intBitsToFloat(int)` method, will produce a floating-point value the same as the argument to `floatToRawIntBits`. Parameters value:float a floating-point number. Returns:int the bits that represent the floating-point number. Annotations @IntrinsicCandidate Since 1.3

public static native int floatToRawIntBits(float value)

Returns a representation of the specified floating-point value according to the IEEE 754 floating-point "single format" bit layout, preserving Not-a-Number (NaN) values.

If the argument is positive infinity, the result is 0x7f800000.

If the argument is negative infinity, the result is 0xff800000.

If the argument is NaN, the result is the integer representing the actual NaN value. Unlike the floatToIntBits method, floatToRawIntBits does not collapse all the bit patterns encoding a NaN to a single "canonical" NaN value.

In all cases, the result is an integer that, when given to the intBitsToFloat(int) method, will produce a floating-point value the same as the argument to floatToRawIntBits.

Parameters

value:float: a floating-point number.

Returns:int

the bits that represent the floating-point number.

Annotations

@IntrinsicCandidate

Since

1.3

floatValue back to summary

floatValue	back to summary
public float floatValue() Implements abstract java.lang.Number.floatValue. Returns the `float` value of this `Float` object. Returns:float the `float` value represented by this object Annotations @IntrinsicCandidate

public float floatValue()

Implements abstract java.lang.Number.floatValue.

Returns the float value of this Float object.

Returns:float

the float value represented by this object

Annotations

@IntrinsicCandidate

hashCode back to summary

hashCode	back to summary
public int hashCode() Overrides java.lang.Object.hashCode. Returns a hash code for this `Float` object. The result is the integer bit representation, exactly as produced by the method `floatToIntBits(float)`, of the primitive `float` value represented by this `Float` object. Returns:int a hash code value for this object. Annotations @Override

public int hashCode()

Overrides java.lang.Object.hashCode.

Returns a hash code for this Float object. The result is the integer bit representation, exactly as produced by the method floatToIntBits(float), of the primitive float value represented by this Float object.

Returns:int

a hash code value for this object.

Annotations

@Override

hashCode back to summary

hashCode	back to summary
public static int hashCode(float value) Returns a hash code for a `float` value; compatible with `Float.hashCode()`. Parameters value:float the value to hash Returns:int a hash code value for a `float` value. Since 1.8

public static int hashCode(float value)

Returns a hash code for a float value; compatible with Float.hashCode().

Parameters

value:float: the value to hash

Returns:int

a hash code value for a float value.

Since

1.8

intBitsToFloat back to summary

intBitsToFloat	back to summary
public static native float intBitsToFloat(int bits) Returns the `float` value corresponding to a given bit representation. The argument is considered to be a representation of a floating-point value according to the IEEE 754 floating-point "single format" bit layout. If the argument is `0x7f800000`, the result is positive infinity. If the argument is `0xff800000`, the result is negative infinity. If the argument is any value in the range `0x7f800001` through `0x7fffffff` or in the range `0xff800001` through `0xffffffff`, the result is a NaN. No IEEE 754 floating-point operation provided by Java can distinguish between two NaN values of the same type with different bit patterns. Distinct values of NaN are only distinguishable by use of the `Float.floatToRawIntBits` method. In all other cases, let s, e, and m be three values that can be computed from the argument: `int s = ((bits >> 31) == 0) ? 1 : -1; int e = ((bits >> 23) & 0xff); int m = (e == 0) ? (bits & 0x7fffff) << 1 : (bits & 0x7fffff) \| 0x800000;` int s = ((bits >> 31) == 0) ? 1 : -1; int e = ((bits >> 23) & 0xff); int m = (e == 0) ? (bits & 0x7fffff) << 1 : (bits & 0x7fffff) \| 0x800000; Then the floating-point result equals the value of the mathematical expression s·m·2^e-150. Note that this method may not be able to return a `float` NaN with exactly same bit pattern as the `int` argument. IEEE 754 distinguishes between two kinds of NaNs, quiet NaNs and signaling NaNs. The differences between the two kinds of NaN are generally not visible in Java. Arithmetic operations on signaling NaNs turn them into quiet NaNs with a different, but often similar, bit pattern. However, on some processors merely copying a signaling NaN also performs that conversion. In particular, copying a signaling NaN to return it to the calling method may perform this conversion. So `intBitsToFloat` may not be able to return a `float` with a signaling NaN bit pattern. Consequently, for some `int` values, `floatToRawIntBits(intBitsToFloat(start))` may not equal `start`. Moreover, which particular bit patterns represent signaling NaNs is platform dependent; although all NaN bit patterns, quiet or signaling, must be in the NaN range identified above. Parameters bits:int an integer. Returns:float the `float` floating-point value with the same bit pattern. Annotations @IntrinsicCandidate

public static native float intBitsToFloat(int bits)

Returns the float value corresponding to a given bit representation. The argument is considered to be a representation of a floating-point value according to the IEEE 754 floating-point "single format" bit layout.

If the argument is 0x7f800000, the result is positive infinity.

If the argument is 0xff800000, the result is negative infinity.

If the argument is any value in the range 0x7f800001 through 0x7fffffff or in the range 0xff800001 through 0xffffffff, the result is a NaN. No IEEE 754 floating-point operation provided by Java can distinguish between two NaN values of the same type with different bit patterns. Distinct values of NaN are only distinguishable by use of the Float.floatToRawIntBits method.

In all other cases, let s, e, and m be three values that can be computed from the argument:

int s = ((bits >> 31) == 0) ? 1 : -1;
int e = ((bits >> 23) & 0xff);
int m = (e == 0) ?
                (bits & 0x7fffff) << 1 :
                (bits & 0x7fffff) | 0x800000;

Then the floating-point result equals the value of the mathematical expression s·m·2^e-150.

Note that this method may not be able to return a float NaN with exactly same bit pattern as the int argument. IEEE 754 distinguishes between two kinds of NaNs, quiet NaNs and signaling NaNs. The differences between the two kinds of NaN are generally not visible in Java. Arithmetic operations on signaling NaNs turn them into quiet NaNs with a different, but often similar, bit pattern. However, on some processors merely copying a signaling NaN also performs that conversion. In particular, copying a signaling NaN to return it to the calling method may perform this conversion. So intBitsToFloat may not be able to return a float with a signaling NaN bit pattern. Consequently, for some int values, floatToRawIntBits(intBitsToFloat(start)) may not equal start. Moreover, which particular bit patterns represent signaling NaNs is platform dependent; although all NaN bit patterns, quiet or signaling, must be in the NaN range identified above.

Parameters

bits:int: an integer.

Returns:float

the float floating-point value with the same bit pattern.

Annotations

@IntrinsicCandidate

intValue back to summary

intValue	back to summary
public int intValue() Implements abstract java.lang.Number.intValue. Returns the value of this `Float` as an `int` after a narrowing primitive conversion. Returns:int the `float` value represented by this object converted to type `int` Java Language Specification 5.1.3 Narrowing Primitive Conversion

public int intValue()

Implements abstract java.lang.Number.intValue.

Returns the value of this Float as an int after a narrowing primitive conversion.

Returns:int: the float value represented by this object converted to type int
Java Language Specification: 5.1.3 Narrowing Primitive Conversion

isFinite back to summary

isFinite	back to summary
public static boolean isFinite(float f) Returns `true` if the argument is a finite floating-point value; returns `false` otherwise (for NaN and infinity arguments). API Note This method corresponds to the isFinite operation defined in IEEE 754. Parameters f:float the `float` value to be tested Returns:boolean `true` if the argument is a finite floating-point value, `false` otherwise. Annotations @IntrinsicCandidate Since 1.8

public static boolean isFinite(float f)

Returns true if the argument is a finite floating-point value; returns false otherwise (for NaN and infinity arguments).

API Note

This method corresponds to the isFinite operation defined in IEEE 754.

Parameters

f:float: the float value to be tested

Returns:boolean

true if the argument is a finite floating-point value, false otherwise.

Annotations

@IntrinsicCandidate

Since

1.8

isInfinite back to summary

isInfinite	back to summary
public static boolean isInfinite(float v) Returns `true` if the specified number is infinitely large in magnitude, `false` otherwise. API Note This method corresponds to the isInfinite operation defined in IEEE 754. Parameters v:float the value to be tested. Returns:boolean `true` if the argument is positive infinity or negative infinity; `false` otherwise. Annotations @IntrinsicCandidate

public static boolean isInfinite(float v)

Returns true if the specified number is infinitely large in magnitude, false otherwise.

API Note

This method corresponds to the isInfinite operation defined in IEEE 754.

Parameters

v:float: the value to be tested.

Returns:boolean

true if the argument is positive infinity or negative infinity; false otherwise.

Annotations

@IntrinsicCandidate

isInfinite back to summary

isInfinite	back to summary
public boolean isInfinite() Returns `true` if this `Float` value is infinitely large in magnitude, `false` otherwise. Returns:boolean `true` if the value represented by this object is positive infinity or negative infinity; `false` otherwise.

public boolean isInfinite()

Returns true if this Float value is infinitely large in magnitude, false otherwise.

Returns:boolean: true if the value represented by this object is positive infinity or negative infinity; false otherwise.

isNaN back to summary

isNaN	back to summary
public static boolean isNaN(float v) Returns `true` if the specified number is a Not-a-Number (NaN) value, `false` otherwise. API Note This method corresponds to the isNaN operation defined in IEEE 754. Parameters v:float the value to be tested. Returns:boolean `true` if the argument is NaN; `false` otherwise.

public static boolean isNaN(float v)

Returns true if the specified number is a Not-a-Number (NaN) value, false otherwise.

API Note

This method corresponds to the isNaN operation defined in IEEE 754.

Parameters

v:float: the value to be tested.

Returns:boolean

true if the argument is NaN; false otherwise.

isNaN back to summary

isNaN	back to summary
public boolean isNaN() Returns `true` if this `Float` value is a Not-a-Number (NaN), `false` otherwise. Returns:boolean `true` if the value represented by this object is NaN; `false` otherwise.

public boolean isNaN()

Returns true if this Float value is a Not-a-Number (NaN), false otherwise.

Returns:boolean: true if the value represented by this object is NaN; false otherwise.

longValue back to summary

longValue	back to summary
public long longValue() Implements abstract java.lang.Number.longValue. Returns value of this `Float` as a `long` after a narrowing primitive conversion. Returns:long the `float` value represented by this object converted to type `long` Java Language Specification 5.1.3 Narrowing Primitive Conversion

public long longValue()

Implements abstract java.lang.Number.longValue.

Returns value of this Float as a long after a narrowing primitive conversion.

Returns:long: the float value represented by this object converted to type long
Java Language Specification: 5.1.3 Narrowing Primitive Conversion

max back to summary

max	back to summary
public static float max(float a, float b) Returns the greater of two `float` values as if by calling `Math.max`. API Note This method corresponds to the maximum operation defined in IEEE 754. Parameters a:float the first operand b:float the second operand Returns:float the greater of `a` and `b` Since 1.8 See Also `java.util.function.BinaryOperator`

public static float max(float a, float b)

Returns the greater of two float values as if by calling Math.max.

API Note

This method corresponds to the maximum operation defined in IEEE 754.

Parameters

a:float: the first operand
b:float: the second operand

Returns:float

the greater of a and b

Since

1.8

See Also

java.util.function.BinaryOperator

min back to summary

min	back to summary
public static float min(float a, float b) Returns the smaller of two `float` values as if by calling `Math.min`. API Note This method corresponds to the minimum operation defined in IEEE 754. Parameters a:float the first operand b:float the second operand Returns:float the smaller of `a` and `b` Since 1.8 See Also `java.util.function.BinaryOperator`

public static float min(float a, float b)

Returns the smaller of two float values as if by calling Math.min.

API Note

This method corresponds to the minimum operation defined in IEEE 754.

Parameters

a:float: the first operand
b:float: the second operand

Returns:float

the smaller of a and b

Since

1.8

See Also

java.util.function.BinaryOperator

parseFloat back to summary

parseFloat	back to summary
public static float parseFloat(String s) throws NumberFormatException Returns a new `float` initialized to the value represented by the specified `String`, as performed by the `valueOf` method of class `Float`. Parameters s:String the string to be parsed. Returns:float the `float` value represented by the string argument. Exceptions NumberFormatException: if the string does not contain a parsable `float`. NullPointerException: if the string is null Since 1.2 See Also `java.lang.Float#valueOf(String)`, `Decimal ↔ Binary Conversion Issues`

public static float parseFloat(String s) throws NumberFormatException

Returns a new float initialized to the value represented by the specified String, as performed by the valueOf method of class Float.

Parameters

s:String: the string to be parsed.

Returns:float

the float value represented by the string argument.

Exceptions

NumberFormatException:: if the string does not contain a parsable float.
NullPointerException:: if the string is null

Since

1.2

resolveConstantDesc back to summary

resolveConstantDesc	back to summary
public Float resolveConstantDesc(MethodHandles.Lookup lookup) Implements java.lang.constant.ConstantDesc.resolveConstantDesc. Resolves this instance as a `ConstantDesc`, the result of which is the instance itself. Parameters lookup:MethodHandles.Lookup ignored Returns:Float the Float instance Annotations @Override Since 12

public Float resolveConstantDesc(MethodHandles.Lookup lookup)

Implements java.lang.constant.ConstantDesc.resolveConstantDesc.

Resolves this instance as a ConstantDesc, the result of which is the instance itself.

Parameters

lookup:MethodHandles.Lookup: ignored

Returns:Float

the Float instance

Annotations

@Override

Since

shortValue back to summary

shortValue	back to summary
public short shortValue() Overrides java.lang.Number.shortValue. Returns the value of this `Float` as a `short` after a narrowing primitive conversion. Returns:short the `float` value represented by this object converted to type `short` Since 1.1 Java Language Specification 5.1.3 Narrowing Primitive Conversion

public short shortValue()

Overrides java.lang.Number.shortValue.

Returns the value of this Float as a short after a narrowing primitive conversion.

Returns:short: the float value represented by this object converted to type short
Since: 1.1
Java Language Specification: 5.1.3 Narrowing Primitive Conversion

sum back to summary

sum	back to summary
public static float sum(float a, float b) Adds two `float` values together as per the + operator. API Note This method corresponds to the addition operation defined in IEEE 754. Parameters a:float the first operand b:float the second operand Returns:float the sum of `a` and `b` Since 1.8 Java Language Specification 4.2.4 Floating-Point Operations See Also `java.util.function.BinaryOperator`

public static float sum(float a, float b)

Adds two float values together as per the + operator.

API Note

This method corresponds to the addition operation defined in IEEE 754.

Parameters

a:float: the first operand
b:float: the second operand

Returns:float

the sum of a and b

Since

1.8

Java Language Specification

4.2.4 Floating-Point Operations

See Also

java.util.function.BinaryOperator

toHexString back to summary

public static String toHexString(float f)

Returns a hexadecimal string representation of the float argument. All characters mentioned below are ASCII characters.

If the argument is NaN, the result is the string "NaN".
Otherwise, the result is a string that represents the sign and magnitude (absolute value) of the argument. If the sign is negative, the first character of the result is '-' ('\u002D'); if the sign is positive, no sign character appears in the result. As for the magnitude m:
- If m is infinity, it is represented by the string "Infinity"; thus, positive infinity produces the result "Infinity" and negative infinity produces the result "-Infinity".
- If m is zero, it is represented by the string "0x0.0p0"; thus, negative zero produces the result "-0x0.0p0" and positive zero produces the result "0x0.0p0".
- If m is a float value with a normalized representation, substrings are used to represent the significand and exponent fields. The significand is represented by the characters "0x1." followed by a lowercase hexadecimal representation of the rest of the significand as a fraction. Trailing zeros in the hexadecimal representation are removed unless all the digits are zero, in which case a single zero is used. Next, the exponent is represented by "p" followed by a decimal string of the unbiased exponent as if produced by a call to Integer.toString on the exponent value.
- If m is a float value with a subnormal representation, the significand is represented by the characters "0x0." followed by a hexadecimal representation of the rest of the significand as a fraction. Trailing zeros in the hexadecimal representation are removed. Next, the exponent is represented by "p-126". Note that there must be at least one nonzero digit in a subnormal significand.

Examples
Floating-point Value	Hexadecimal String
`1.0`	`0x1.0p0`
`-1.0`	`-0x1.0p0`
`2.0`	`0x1.0p1`
`3.0`	`0x1.8p1`
`0.5`	`0x1.0p-1`
`0.25`	`0x1.0p-2`
`Float.MAX_VALUE`	`0x1.fffffep127`
`Minimum Normal Value`	`0x1.0p-126`
`Maximum Subnormal Value`	`0x0.fffffep-126`
`Float.MIN_VALUE`	`0x0.000002p-126`

Parameters

f:float: the float to be converted.

Returns:String

a hex string representation of the argument.

Author

Joseph D. Darcy

Since

1.5

toString back to summary

toString	back to summary
public static String toString(float f) Returns a string representation of the `float` argument. All characters mentioned below are ASCII characters. If the argument is NaN, the result is the string "`NaN`". Otherwise, the result is a string that represents the sign and magnitude (absolute value) of the argument. If the sign is negative, the first character of the result is '`-`' (`'\u002D'`); if the sign is positive, no sign character appears in the result. As for the magnitude m: If m is infinity, it is represented by the characters `"Infinity"`; thus, positive infinity produces the result `"Infinity"` and negative infinity produces the result `"-Infinity"`. If m is zero, it is represented by the characters `"0.0"`; thus, negative zero produces the result `"-0.0"` and positive zero produces the result `"0.0"`. Otherwise m is positive and finite. It is converted to a string in two stages: Selection of a decimal: A well-defined decimal d_m is selected to represent m. This decimal is (almost always) the shortest one that rounds to m according to the round to nearest rounding policy of IEEE 754 floating-point arithmetic. Formatting as a string: The decimal d_m is formatted as a string, either in plain or in computerized scientific notation, depending on its value. A decimal is a number of the form s×10ⁱ for some (unique) integers s > 0 and i such that s is not a multiple of 10. These integers are the significand and the exponent, respectively, of the decimal. The length of the decimal is the (unique) positive integer n meeting 10^n-1 ≤ s < 10ⁿ. The decimal d_m for a finite positive m is defined as follows: Let R be the set of all decimals that round to m according to the usual round to nearest rounding policy of IEEE 754 floating-point arithmetic. Let p be the minimal length over all decimals in R. When p ≥ 2, let T be the set of all decimals in R with length p. Otherwise, let T be the set of all decimals in R with length 1 or 2. Define d_m as the decimal in T that is closest to m. Or if there are two such decimals in T, select the one with the even significand. The (uniquely) selected decimal d_m is then formatted. Let s, i and n be the significand, exponent and length of d_m, respectively. Further, let e = n + i - 1 and let s₁…s_n be the usual decimal expansion of s. Note that s₁ ≠ 0 and s_n ≠ 0. Below, the decimal point `'.'` is `'\u002E'` and the exponent indicator `'E'` is `'\u0045'`. Case -3 ≤ e < 0: d_m is formatted as `0.0`…`0`s₁…s_n, where there are exactly -(n + i) zeroes between the decimal point and s₁. For example, 123 × 10^-4 is formatted as `0.0123`. Case 0 ≤ e < 7: Subcase i ≥ 0: d_m is formatted as s₁…s_n`0`…`0.0`, where there are exactly i zeroes between s_n and the decimal point. For example, 123 × 10² is formatted as `12300.0`. Subcase i < 0: d_m is formatted as s₁…s_n+i`.`s_n+i+1…s_n, where there are exactly -i digits to the right of the decimal point. For example, 123 × 10^-1 is formatted as `12.3`. Case e < -3 or e ≥ 7: computerized scientific notation is used to format d_m. Here e is formatted as by `Integer#toString(int)`. Subcase n = 1: d_m is formatted as s₁`.0E`e. For example, 1 × 10²³ is formatted as `1.0E23`. Subcase n > 1: d_m is formatted as s₁`.`s₂…s_n`E`e. For example, 123 × 10^-21 is formatted as `1.23E-19`. To create localized string representations of a floating-point value, use subclasses of `java.text.NumberFormat`. Parameters f:float the `float` to be converted. Returns:String a string representation of the argument.

public static String toString(float f)

Returns a string representation of the float argument. All characters mentioned below are ASCII characters.

If the argument is NaN, the result is the string "NaN".
Otherwise, the result is a string that represents the sign and magnitude (absolute value) of the argument. If the sign is negative, the first character of the result is '-' ('\u002D'); if the sign is positive, no sign character appears in the result. As for the magnitude m:
- If m is infinity, it is represented by the characters "Infinity"; thus, positive infinity produces the result "Infinity" and negative infinity produces the result "-Infinity".
- If m is zero, it is represented by the characters "0.0"; thus, negative zero produces the result "-0.0" and positive zero produces the result "0.0".
- Otherwise m is positive and finite. It is converted to a string in two stages:
  - Selection of a decimal: A well-defined decimal d_m is selected to represent m. This decimal is (almost always) the shortest one that rounds to m according to the round to nearest rounding policy of IEEE 754 floating-point arithmetic.
  - Formatting as a string: The decimal d_m is formatted as a string, either in plain or in computerized scientific notation, depending on its value.

A decimal is a number of the form s×10ⁱ for some (unique) integers s > 0 and i such that s is not a multiple of 10. These integers are the significand and the exponent, respectively, of the decimal. The length of the decimal is the (unique) positive integer n meeting 10^n-1 ≤ s < 10ⁿ.

The decimal d_m for a finite positive m is defined as follows:

Let R be the set of all decimals that round to m according to the usual round to nearest rounding policy of IEEE 754 floating-point arithmetic.
Let p be the minimal length over all decimals in R.
When p ≥ 2, let T be the set of all decimals in R with length p. Otherwise, let T be the set of all decimals in R with length 1 or 2.
Define d_m as the decimal in T that is closest to m. Or if there are two such decimals in T, select the one with the even significand.

The (uniquely) selected decimal d_m is then formatted. Let s, i and n be the significand, exponent and length of d_m, respectively. Further, let e = n + i - 1 and let s₁…s_n be the usual decimal expansion of s. Note that s₁ ≠ 0 and s_n ≠ 0. Below, the decimal point '.' is '\u002E' and the exponent indicator 'E' is '\u0045'.

Case -3 ≤ e < 0: d_m is formatted as 0.0…0s₁…s_n, where there are exactly -(n + i) zeroes between the decimal point and s₁. For example, 123 × 10^-4 is formatted as 0.0123.
Case 0 ≤ e < 7:
- Subcase i ≥ 0: d_m is formatted as s₁…s_n0…0.0, where there are exactly i zeroes between s_n and the decimal point. For example, 123 × 10² is formatted as 12300.0.
- Subcase i < 0: d_m is formatted as s₁…s_n+i.s_n+i+1…s_n, where there are exactly -i digits to the right of the decimal point. For example, 123 × 10^-1 is formatted as 12.3.
Case e < -3 or e ≥ 7: computerized scientific notation is used to format d_m. Here e is formatted as by Integer#toString(int).
- Subcase n = 1: d_m is formatted as s₁.0Ee. For example, 1 × 10²³ is formatted as 1.0E23.
- Subcase n > 1: d_m is formatted as s₁.s₂…s_nEe. For example, 123 × 10^-21 is formatted as 1.23E-19.

To create localized string representations of a floating-point value, use subclasses of java.text.NumberFormat.

Parameters

f:float: the float to be converted.

Returns:String

a string representation of the argument.

toString back to summary

public String toString()

Overrides java.lang.Object.toString.

Returns a string representation of this Float object. The primitive float value represented by this object is converted to a String exactly as if by the method toString of one argument.

Returns:String: a String representation of this object.
See Also: java.lang.Float#toString(float)

valueOf back to summary

public static Float valueOf(String s) throws NumberFormatException

Returns a Float object holding the float value represented by the argument string s.

If s is null, then a NullPointerException is thrown.

Leading and trailing whitespace characters in s are ignored. Whitespace is removed as if by the String#trim method; that is, both ASCII space and control characters are removed. The rest of s should constitute a FloatValue as described by the lexical syntax rules:

FloatValue:
Sign_opt NaN
Sign_opt Infinity
Sign_opt FloatingPointLiteral
Sign_opt HexFloatingPointLiteral
SignedInteger

HexFloatingPointLiteral:
HexSignificand BinaryExponent FloatTypeSuffix_opt

HexSignificand:
HexNumeral
HexNumeral .
0x HexDigits_opt . HexDigits
0X HexDigits_opt . HexDigits

BinaryExponent:
BinaryExponentIndicator SignedInteger

BinaryExponentIndicator:
p
P

where Sign, FloatingPointLiteral, HexNumeral, HexDigits, SignedInteger and FloatTypeSuffix are as defined in the lexical structure sections of The Java Language Specification, except that underscores are not accepted between digits. If s does not have the form of a FloatValue, then a NumberFormatException is thrown. Otherwise, s is regarded as representing an exact decimal value in the usual "computerized scientific notation" or as an exact hexadecimal value; this exact numerical value is then conceptually converted to an "infinitely precise" binary value that is then rounded to type float by the usual round-to-nearest rule of IEEE 754 floating-point arithmetic, which includes preserving the sign of a zero value. Note that the round-to-nearest rule also implies overflow and underflow behaviour; if the exact value of s is large enough in magnitude (greater than or equal to (MAX_VALUE + ulp(MAX_VALUE)/2), rounding to float will result in an infinity and if the exact value of s is small enough in magnitude (less than or equal to MIN_VALUE/2), rounding to float will result in a zero. Finally, after rounding a Float object representing this float value is returned.

Note that trailing format specifiers, specifiers that determine the type of a floating-point literal (1.0f is a float value; 1.0d is a double value), do not influence the results of this method. In other words, the numerical value of the input string is converted directly to the target floating-point type. In general, the two-step sequence of conversions, string to double followed by double to float, is not equivalent to converting a string directly to float. For example, if first converted to an intermediate double and then to float, the string
"1.00000017881393421514957253748434595763683319091796875001d"
results in the float value 1.0000002f; if the string is converted directly to float, 1.0000001f results.

To avoid calling this method on an invalid string and having a NumberFormatException be thrown, the documentation for Double.valueOf lists a regular expression which can be used to screen the input.

API Note

To interpret localized string representations of a floating-point value, or string representations that have non-ASCII digits, use java.text.NumberFormat. For example,

NumberFormat.getInstance(l).parse(s).floatValue();

where l is the desired locale, or java.util.Locale#ROOT if locale insensitive.

Parameters

s:String: the string to be parsed.

Returns:Float

a Float object holding the value represented by the String argument.

Exceptions

NumberFormatException:: if the string does not contain a parsable number.

See Also

Decimal ↔ Binary Conversion Issues

valueOf back to summary

public static Float valueOf(float f)

Returns a Float instance representing the specified float value. If a new Float instance is not required, this method should generally be used in preference to the constructor Float(float), as this method is likely to yield significantly better space and time performance by caching frequently requested values.

Parameters

f:float: a float value.

Returns:Float

a Float instance representing f.

Annotations

@IntrinsicCandidate

Since

1.5

public final Class Float

Floating-point Equality, Equivalence, and Comparison

Decimal ↔ Binary Conversion Issues

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

IEEE 754 binary16 format