Java Reference
In-Depth Information
Math.random() generates a different sequence each time an application starts run-
ning.
Tip Random(long seed) gives you the opportunity to reuse the same seed
value,allowingthesamesequenceofrandomnumberstobegenerated.Youwillfind
thiscapabilityusefulwhendebuggingafaultyapplicationthatinvolvesrandomnum-
bers.
Random(long seed) callsthe void setSeed(long seed) methodtoset
theseedtothespecifiedvalue.Ifyoucall setSeed() afterinstantiating Random ,the
random number generator is reset to the state that it was in immediately after calling
Random(long seed) .
The previous code fragment demonstrates Random 's double nextDouble()
method, which returns the next pseudorandom, uniformly distributed double precision
floating-point value between 0.0 and 1.0 in this random number generator's sequence.
Random also declares the following methods for returning other kinds of values:
boolean nextBoolean() returnsthenextpseudorandom,uniformlydis-
tributedBooleanvalueinthisrandomnumbergenerator'ssequence.Valuestrue
and false are generated with (approximately) equal probability.
void nextBytes(byte[] bytes) generatespseudorandombyteinteger
values and stores them in the bytes array. The number of generated bytes is
equal to the length of the bytes array.
float nextFloat() returnsthenextpseudorandom,uniformlydistributed
floating-pointvaluebetween0.0and1.0inthisrandomnumbergenerator'sse-
quence.
double nextGaussian() returnsthenextpseudorandom,Gaussian(“nor-
mally”) distributed double precision floating-point value with mean 0.0 and
standard deviation 1.0 in this random number generator's sequence.
int nextInt() returns the next pseudorandom, uniformly distributed in-
tegervalueinthisrandomnumbergenerator'ssequence.All2 32 possibleinteger
values are generated with (approximately) equal probability.
int nextInt(int n) returns a pseudorandom, uniformly distributed in-
teger value between 0 (inclusive) and the specified value (exclusive), drawn
from this random number generator's sequence. All n possible integer values
are generated with (approximately) equal probability.
Search WWH ::




Custom Search