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`java.lang.Float`

public final class`extends Number { public static final float`

Float`= 1.4e-45f; public static final float`

MIN_VALUE`= 3.4028235e+38f; public static final float`

MAX_VALUE`= -1.0f/0.0f; public static final float`

NEGATIVE_INFINITY`= 1.0f/0.0f; public static final float`

POSITIVE_INFINITY`= 0.0f/0.0f; public`

NaN`(float value); public`

Float`(double value); public`

Float`(String s) throws NumberFormatException; public String`

Float`(); public boolean`

toString`(Object obj); public int`

equals`(); public int`

hashCode`(); public long`

intValue`(); public float`

longValue`(); public double`

floatValue`(); public static String`

doubleValue`(float f); public static Float`

toString`(String s) throws NullPointerException, NumberFormatException; public boolean`

valueOf`(); public static boolean`

isNaN`(float v); public boolean`

isNaN`(); public static boolean`

isInfinite`(float v); public static int`

isInfinite`(float value); public static float`

floatToIntBits`(int bits); }`

intBitsToFloat

**20.9.1 ** `public static final float `

= 1.4e-45f;**MIN_VALUE**

The constant value of this field is the smallest positive nonzero value of type
`float`

. It is equal to the value returned by `Float.intBitsToFloat(0x1)`

.

**20.9.2 ** `public static final float `

= 3.4028235e+38f;**MAX_VALUE**

The constant value of this field is the largest positive finite value of type `float`

. It
is equal to the value returned by `Float.intBitsToFloat(0x7f7fffff)`

.

**20.9.3 ** `public static final float `

=**NEGATIVE_INFINITY**

-1.0f/0.0f;

The constant value of this field is the negative infinity of type `float`

. It is equal to
the value returned by `Float.intBitsToFloat(0xff800000)`

.

**20.9.4 ** `public static final float `

=**POSITIVE_INFINITY**

1.0f/0.0f;

The constant value of this field is the positive infinity of type `float`

. It is equal to
the value returned by `Float.intBitsToFloat(0x7f800000)`

.

**20.9.5 ** `public static final float `

= 0.0f/0.0f;**NaN**

The constant value of this field is the Not-a-Number value of type `float`

. It is
equal to the value returned by `Float.intBitsToFloat(0x7fc00000)`

.

**20.9.6 ** `public `

(float value)**Float**

This constructor initializes a newly created `Float`

object so that it represents the
primitive value that is the argument.

**20.9.7 ** `public `

(double value)**Float**

This constructor initializes a newly created `Float`

object so that it represents the
result of narrowing (§5.1.3) the argument from type `double`

to type `float`

.

**20.9.8 ** `public `

(String s) throws NumberFormatException**Float**

This constructor initializes a newly created `Float`

object so that it represents the
floating-point value of type `float`

represented by the string. The string is converted
to a `float`

value in exactly the manner used by the `valueOf`

method
(§20.9.17).

**20.9.9 ** `public String `

()**toString**

The primitive `float`

value represented by this `Float`

object is converted to a
string exactly as if by the method `toString`

of one argument (§20.9.16).

Overrides the `toString`

method of `Object`

(§20.1.2).

**20.9.10 ** `public boolean `

(Object obj)**equals**

The result is `true`

if and only if the argument is not `null`

and is a `Float`

object
that represents the same `float`

value as this `Float`

object. For this purpose, two
`float`

values are considered to be the same if and only if the method
`floatToIntBits`

(§20.9.22) returns the same `int`

value when applied to each.
Note that even though the `==`

operator returns `false`

if both operands are NaN,
this `equals`

method will return `true`

if this `Float`

object and the argument are
both `Float`

objects that represent NaN. On the other hand, even though the `==`

operator returns `true`

if one operand is positive zero and the other is negative
zero, this `equals`

method will return `false`

if this `Float`

object and the argument
represent zeroes of different sign. This definition allows hashtables to operate
properly.

Overrides the `equals`

method of `Object`

(§20.1.3).

**20.9.11 ** `public int `

()**hashCode**

The result is the integer bit representation, exactly as produced by the method
`floatToIntBits`

(§20.9.22), of the primitive `float`

value represented by this
`Float`

object.

Overrides the `hashCode`

method of `Object`

(§20.1.4).

**20.9.12 ** `public int `

()**intValue**

The `float`

value represented by this `Float`

object is converted (§5.1.3) to type
`int`

and the result of the conversion is returned.

Overrides the `intValue`

method of `Number`

(§20.6.1).

**20.9.13 ** `public long `

()**longValue**

The `float`

value represented by this `Float`

object is converted (§5.1.3) to type
`long`

and the result of the conversion is returned.

Overrides the `longValue`

method of `Number`

(§20.6.2).

**20.9.14 ** `public float `

()**floatValue**

The `float`

value represented by this `Float`

object is returned.

Overrides the `floatValue`

method of `Number`

(§20.6.3).

**20.9.15 ** `public double `

()**doubleValue**

The `float`

value represented by this `Float`

object is converted (§5.1.2) to type
`double`

and the result of the conversion is returned.

Overrides the `doubleValue`

method of `Number`

(§20.6.4).

**20.9.16 ** `public static String `

(float f)**toString**

The argument is converted to a readable string format as follows. All characters and characters in strings 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"`

. - If
*m*is greater than or equal to but less than , then it is represented as the integer part of*m*, in decimal form with no leading zeroes, followed by`'.'`

(`\u002E`

), followed by one or more decimal digits representing the fractional part of*m*. - If
*m*is less than or not less than , then it is represented in so-called "computerized scientific notation." Let*n*be the unique integer such that ; then let*a*be the mathematically exact quotient of*m*and so that . The magnitude is then represented as the integer part of*a*, as a single decimal digit, followed by`'.'`

(`\u002E`

), followed by decimal digits representing the fractional part of*a*, followed by the letter`'E'`

(`\u0045`

), followed by a representation of*n*as a decimal integer, as produced by the method`Integer.toString`

of one argument (§20.7.12).

- If

`float`

. That is, suppose that `float`

value nearest to `float`

values are equally close to `0`

.
[This specification for the method `toString`

is scheduled for introduction in Java version 1.1. In previous versions of Java, this method produces `Inf`

instead of `Infinity`

for infinite values. Also, it renders finite values in the same form as the `%g`

format of the `printf`

function in the C programming language, which can lose precision because it produces at most six digits after the decimal point.]

**20.9.17 ** `public static Float `

(String s)**valueOf**

throws NullPointerException, NumberFormatException

The string `s`

is interpreted as the representation of a floating-point value and a
`Float`

object representing that value is created and returned.

If `s`

is `null`

, then a `NullPointerException`

is thrown.

Leading and trailing whitespace (§20.5.19) characters in `s`

are ignored. The rest of `s`

should constitute a *FloatValue* as described by the lexical syntax rules:

whereFloatValue:

Sign_{opt}

Digits`.`

Digits_{opt}

ExponentPart_{opt }Sign_{opt}`.`

Digits

ExponentPart_{opt }

`NumberFormatException`

is thrown. Otherwise,
it is regarded as representing an exact decimal value in the usual "computerized
scientific notation"; this exact decimal 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. Finally, a new object
of class `Float`

is created to represent this `float`

value.
Note that neither `F`

nor `f`

is permitted to appear in `s`

as a type indicator, as would be permitted in Java source code (§3.10.1).

**20.9.18 ** `public boolean `

()**isNaN**

The result is `true`

if and only if the value represented by this `Float`

object is
NaN.

**20.9.19 ** `public static boolean `

(float v)**isNaN**

The result is `true`

if and only if the value of the argument is NaN.

**20.9.20 ** `public boolean `

()**isInfinite**

The result is `true`

if and only if the value represented by this `Float`

object is positive
infinity or negative infinity.

**20.9.21 ** `public static boolean `

(float v)**isInfinite**

The result is `true`

if and only if the value of the argument is positive infinity or
negative infinity.

**20.9.22 ** `public static int `

(float value)**floatToIntBits**

The result is a representation of the floating-point argument 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 will be
`0x7f800000`

. - If the argument is negative infinity, the result will be
`0xff800000`

. - If the argument is NaN, the result will be
`0x7fc00000`

.

`intBitsToFloat`

method (§20.9.23), will produce a floating-point value equal to the argument to `floatToIntBits`

.**20.9.23 ** `public static float `

(int bits)**intBitsToFloat**

The argument is considered to be a representation of a floating-point value according to the IEEE 754 floating-point "single format" bit layout. That floating-point value is returned as the result.

- If the argument is
`0x7f800000`

, the result will be positive infinity. - If the argument is
`0xff800000`

, the result will be negative infinity. - If the argument is any value in the range
`0x7f800001`

through`0x7fffffff`

or in the range`0xff800001`

through`0xffffffff`

, the result will be NaN. (All IEEE 754 NaN values are, in effect, lumped together by the Java language into a single value called NaN.) - 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 .

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Java Language Specification (HTML generated by Suzette Pelouch on February 24, 1998)

*Copyright © 1996 Sun Microsystems, Inc.
All rights reserved*

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