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java.util
public class
public class
java.util.Random
| java.lang.Object | ||
| java.util.Random | Serializable | |
This class provides methods that generates pseudo-random numbers of different types, such as int, long, double and float using either
Known Direct Subclasses
See Also
Summary
Public Constructors
| Random() | ||||||
| Construct a random generator with the current time of day in milliseconds as the initial state. | ||||||
| Random(long seed) | ||||||
Construct a random generator with the given seed as the
initial state. |
||||||
Public Methods
| boolean | nextBoolean() | |||||
| Returns the next pseudo-random, uniformly distributed boolean value generated by this generator. | ||||||
| void | nextBytes(byte[] buf) | |||||
| Modifies the byte array by a random sequence of bytes generated by this random number generator. | ||||||
| double | nextDouble() | |||||
| Generates a normally distributed random double number between 0.0 inclusively and 1.0 exclusively. | ||||||
| float | nextFloat() | |||||
| Generates a normally distributed random float number between 0.0 inclusively and 1.0 exclusively. | ||||||
| synchronized | double | nextGaussian() | ||||
pseudo-randomly generates (approximately) a normally distributed
double value with mean 0.0 and a standard deviation value
of 1.0 using the polar method of G. |
||||||
| int | nextInt(int n) | |||||
Returns to the caller a new pseudo-random integer value which is uniformly
distributed between 0 (inclusively) and the value of n
(exclusively). |
||||||
| int | nextInt() | |||||
Generates a uniformly distributed 32-bit int value from
the this random number sequence. |
||||||
| long | nextLong() | |||||
Generates a uniformly distributed 64-bit int value from
the this random number sequence. |
||||||
| synchronized | void | setSeed(long seed) | ||||
| Modifies the seed using linear congruential formula presented in The Art of Computer Programming, Volume 2, Section 3.2.1. | ||||||
Protected Methods
| synchronized | int | next(int bits) | ||||
Returns a pseudo-random uniformly distributed int value of
the number of bits specified by the argument bits as
described by Donald E. |
||||||
Methods inherited
from class
java.lang.Object
Details
Public Constructors
public Random()
Construct a random generator with the current time of day in milliseconds
as the initial state.
See Also
public Random(long seed)
Construct a random generator with the given
seed as the
initial state.
Parameters
| seed | the seed that will determine the initial state of this random number generator |
|---|
See Also
Public Methods
public boolean nextBoolean()
Returns the next pseudo-random, uniformly distributed boolean value
generated by this generator.
Returns
- boolean a pseudo-random, uniformly distributed boolean value
public void nextBytes(byte[] buf)
Modifies the byte array by a random sequence of bytes generated by this
random number generator.
Parameters
| buf | non-null array to contain the new random bytes |
|---|
See Also
public double nextDouble()
Generates a normally distributed random double number between 0.0
inclusively and 1.0 exclusively.
Returns
- double
See Also
public float nextFloat()
Generates a normally distributed random float number between 0.0
inclusively and 1.0 exclusively.
Returns
- float a random float number between 0.0 and 1.0
See Also
public synchronized double nextGaussian()
pseudo-randomly generates (approximately) a normally distributed
double value with mean 0.0 and a standard deviation value
of 1.0 using the polar method of G. E. P. Box, M.
E. Muller, and G. Marsaglia, as described by Donald E. Knuth in The
Art of Computer Programming, Volume 2: Seminumerical Algorithms,
section 3.4.1, subsection C, algorithm P
Returns
- double
See Also
public int nextInt(int n)
Returns to the caller a new pseudo-random integer value which is uniformly
distributed between 0 (inclusively) and the value of
n
(exclusively).
Parameters
| n | int |
|---|
Returns
- int
public int nextInt()
Generates a uniformly distributed 32-bit
int value from
the this random number sequence.
Returns
- int uniformly distributed
intvalue
See Also
public long nextLong()
Generates a uniformly distributed 64-bit
int value from
the this random number sequence.
Returns
- 64-bit
intrandom number
See Also
public synchronized void setSeed(long seed)
Modifies the seed using linear congruential formula presented in The
Art of Computer Programming, Volume 2, Section 3.2.1.
Parameters
| seed | the seed that alters the state of the random number generator |
|---|
See Also
Protected Methods
protected synchronized int next(int bits)
Returns a pseudo-random uniformly distributed
int value of
the number of bits specified by the argument bits as
described by Donald E. Knuth in The Art of Computer Programming,
Volume 2: Seminumerical Algorithms, section 3.2.1.
Parameters
| bits | number of bits of the returned value |
|---|
Returns
- int a pseudo-random generated int number