THE PACKAGE JAVA.UTIL

java.util.BitSet

21.2

21.2.3

public String toString()

For every index for which this

BitSet

 contains a bit in the set state, the decimal

representation of that index is included in the result. Such indices are listed in

order from lowest to highest, separated by  

,

  (a comma and a space) and sur 

rounded by braces, resulting in the usual mathematical notation for a set of inte 

gers.

Overrides the

toString

 method of

Object

 ( 20.1.2).

Example:

BitSet drPepper = new BitSet();

Now

drPepper.toString()

 returns

"{}"

.

drPepper.set(2);

Now

drPepper.toString()

 returns

"{2}"

.

drPepper.set(4);

drPepper.set(10);

Now

drPepper.toString()

 returns

"{2, 4, 10}"

.

21.2.4

public boolean equals(Object obj)

The result is

true

 if and only if the argument is not

null

 and is a

BitSet

 object

such that, for every nonnegative

int

 index

k

:

((BitSet)obj).get(k) == this.get(k)

Overrides the

equals

 method of

Object

 ( 20.1.3).

21.2.5

public int hashCode()

The hash code depends only on which bits have been set within this

BitSet

. The

algorithm used to compute it may be described as follows.

Suppose the bits in the

BitSet

 were to be stored in an array of

long

 integers

called, say,

bits

, in such a manner that bit

k

 is set in the

BitSet

 (for nonnegative

values of

k

) if and only if the expression:

((k>>6) < bits.length) &&

((bits[k>>6] & (1L << (bit & 0x3F))) != 0)

is true. Then the following definition of the

hashCode

 method would be a correct

implementation of the actual algorithm:

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