Class java.lang.Float





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Class java.lang.Float


java.lang.Object
|
+----java.lang.Number
|
+----java.lang.Float



public final class Float
extends Number

The Float class wraps a value of primitive type float in
an object. An object of type Float contains a single
field whose type is float.

In addition, this class provides several methods for converting a
float to a String and a
String to a float, as well as other
constants and methods useful when dealing with a
float.








MAX_VALUE
The largest positive value of type float.

MIN_VALUE
The smallest positive value of type float.

NaN

The NaN value of type float.

NEGATIVE_INFINITY
The negative infinity of type float.

POSITIVE_INFINITY
The positive infinity of type float.

TYPE
The Class object representing the primitive type float.






Float(double)
Constructs a newly allocated Floatobject that
represents the argument converted to type float.

Float(float)
Constructs a newly allocated Float object that
represents the primitive float argument.

Float(String)
Constructs a newly allocated Float object that
represents the floating- point value of type float
represented by the string.






byteValue()
Returns the value of this Float as a byte (by casting to a byte).

doubleValue()
Returns the double value of this Float.

equals(Object)
Compares this object against some other object.

floatToIntBits(float)
Returns the bit represention of a single-float value.

floatValue()
Returns the float value of this Float object.

hashCode()
Returns a hashcode for this Float.

intBitsToFloat(int)
Returns the single-float corresponding to a given bit represention.

intValue()
Returns the integer value of this Float (by casting to an int).

isInfinite()
Returns true if this Float value is infinitely large in magnitude.

isInfinite(float)
Returns true if the specified number is infinitely large in magnitude.

isNaN()
Returns true if this Float value is Not-a-Number (NaN).

isNaN(float)
Returns true if the specified number is the special Not-a-Number (NaN)
value.

longValue()
Returns the long value of this Float (by casting to a long).

shortValue()
Returns the value of this Float as a short (by casting to a short).

toString()
Returns a String representation of this Float object.

toString(float)
Returns a String representation for the specified float value.

valueOf(String)
Returns the floating point value represented by the specified String.






POSITIVE_INFINITY

public static final float POSITIVE_INFINITY


The positive infinity of type float.


NEGATIVE_INFINITY

public static final float NEGATIVE_INFINITY


The negative infinity of type float.


NaN

public static final float NaN


The NaN value of type float.


MAX_VALUE

public static final float MAX_VALUE


The largest positive value of type float.


MIN_VALUE

public static final float MIN_VALUE


The smallest positive value of type float.


TYPE

public static final Class TYPE


The Class object representing the primitive type float.







Float

public Float(float value)


Constructs a newly allocated Float object that
represents the primitive float argument.


Parameters:
value - the value to be represented by the Float.



Float

public Float(double value)


Constructs a newly allocated Floatobject that
represents the argument converted to type float.


Parameters:
value - the value to be represented by the Float.



Float

public Float(String s) throws NumberFormatException


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 - a string to be converted to a Float.
Throws: NumberFormatException
if the string does not contain a
parsable number.
See Also:
valueOf







toString

public static String toString(float f)


Returns a String representation for the specified float value.

The values NaN, NEGATIVE_INFINITY,
POSITIVE_INFINITY, -0.0, and
+0.0 are represented by the strings
"NaN", "-Infinity",
"Infinity", "-0.0", and
"0.0", respectively.

If d is in the range
10-3 <=
|d| <= 107,
then it is converted to a String in the style
[-]ddd.ddd. Otherwise, it is converted to a
string in the style [-]m.ddddE±xx.

There is always a minimum of 1 digit after the decimal point. The
number of digits is the minimum needed to uniquely distinguish the
argument value from adjacent values of type float.


Parameters:
d - the float to be converted.
Returns:
a string representation of the argument.



valueOf

public static Float valueOf(String s) throws NumberFormatException


Returns the floating point value represented by the specified String.


Parameters:
s - the string to be parsed.
Returns:
a newly constructed Float initialized to the
value represented by the String argument.
Throws: NumberFormatException
if the string does not contain a
parsable number.



isNaN

public static boolean isNaN(float v)


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


Parameters:
v - the value to be tested.
Returns:
true if the argument is NaN;
false otherwise.



isInfinite

public static boolean isInfinite(float v)


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


Parameters:
v - the value to be tested.
Returns:
true if the argument is positive infinity or
negative infinity; false otherwise.



isNaN

public boolean isNaN()


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


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



isInfinite

public boolean isInfinite()


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


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



toString

public String 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:
a String representation of this object.
Overrides:
toString in class Object
See Also:
toString



byteValue

public byte byteValue()


Returns the value of this Float as a byte (by casting to a byte).


Overrides:
byteValue in class Number



shortValue

public short shortValue()


Returns the value of this Float as a short (by casting to a short).


Overrides:
shortValue in class Number



intValue

public int intValue()


Returns the integer value of this Float (by casting to an int).


Returns:
the float value represented by this object
converted to type int and the result of the
conversion is returned.
Overrides:
intValue in class Number



longValue

public long longValue()


Returns the long value of this Float (by casting to a long).


Returns:
the float value represented by this object is
converted to type long and the result of the
conversion is returned.
Overrides:
longValue in class Number



floatValue

public float floatValue()


Returns the float value of this Float object.


Returns:
the float value represented by this object.
Overrides:
floatValue in class Number



doubleValue

public double doubleValue()


Returns the double value of this Float.


Overrides:
doubleValue in class Number



hashCode

public int hashCode()


Returns a hashcode for this Float.


Returns:
a hash code value for this object.
Overrides:
hashCode in class Object



equals

public boolean equals(Object obj)


Compares this object against some other object.
The result is true if and only if the argument is
not null and is a Float object that
represents a float that has the identical bit pattern
to the bit pattern of the float represented by this
object.

Note that in most cases, for two instances of class
Float, f1 and f2, the value
of f1.equals(f2) is true if and only if

f1.floatValue() == f2.floatValue()


also has the value true. However, there are two exceptions:

If f1 and f2 both represent
Float.NaN, then the equals method returns
true, even though Float.NaN==Float.NaN
has the value false.
If f1 represents +0.0f while
f2 represents -0.0f, or vice versa,
the equal test has the value false,
even though 0.0f==-0.0f has the value true.



Returns:
true if the objects are the same;
false otherwise.
Overrides:
equals in class Object
See Also:
floatToIntBits



floatToIntBits

public static native int floatToIntBits(float value)


Returns the bit represention of a single-float value.
The result is a representation of the floating-point argument
according to the IEEE 754 floating-point "single
precision" bit layout.

Bit 31 represents the sign of the floating-point number. Bits
30-23 represent the exponent. Bits 22-0 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.


Parameters:
value - a floating-point number.
Returns:
the bits that represent the floating-point number.



intBitsToFloat

public static native float intBitsToFloat(int bits)


Returns the single-float corresponding to a given bit represention.
The argument is considered to be a representation of a
floating-point value according to the IEEE 754 floating-point
"single precision" 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 0x7f8fffff or in the range
0xff800001 through 0xff8fffff, the result is
NaN. All IEEE 754 NaN values are, in effect, lumped together by
the Java language into a single value.


Parameters:
bits - an integer.
Returns:
the single-format floating-point value with the same bit
pattern.




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