20.10

java.lang.Double

THE PACKAGE JAVA.LANG

20.10.9

public boolean equals(Object obj)

The result is

true

 if and only if the argument is not

null

 and is a

Double

 object

that represents the same

double

 value as this

Double

 object. For this purpose,

two

double

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

doubleToLongBits

( 20.10.21) returns the same

long

 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

Double

 object and the argument

are both

Double

 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

Double

 object and the argu 

ment represent zeroes of different sign. This allows hashtables to operate properly.

Overrides the

equals

 method of

Object

 ( 20.1.3).

20.10.10

public int hashCode()

The result is the exclusive OR of the two halves of the long integer bit representa 

tion, exactly as produced by the method

doubleToLongBits

 ( 20.10.21), of the

primitive

double

 value represented by this

Double

 object. That is, the hashcode is

the value of the expression:

(int)(v^(v>>>32))

where

v

 is defined by:

long v = Double.doubleToLongBits(this.longValue());

Overrides the

hashCode

 method of

Object

 ( 20.1.4).

20.10.11

public int intValue()

The

double

 value represented by this

Double

 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).

20.10.12

public long longValue()

The

double

 value represented by this

Double

 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).

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