Java Reference
In-Depth Information
•
int nextInt()
: Returns a pseudo-random number integer. Values are uniformly distributed
across the range of possible values of type
int.
•
int nextInt(int limit)
: Returns a pseudo-random number integer that is greater than or equal
to 0, and less than
limit
— very useful for creating random array index values.
•
long nextLong()():
The same as
nextInt()
except values are of type
long
.
•
float nextFloat()
: Returns a pseudo-random
float
value. Values are uniformly distributed
across the range 0.0f to 1.0f, excluding 1.0f.
•
double nextDouble()
: Returns a pseudo-random number of type
double
. Values are uniformly
distributed across the range 0.0 to 1.0, excluding 1.0.
•
double nextGaussian()
: Returns a pseudo-random number selected from a Gaussian distribu-
tion. Values generated have a mean of 0.0 and a standard deviation of 1.0.
•
void nextBytes(byte[] bytes)
: Fills the array,
bytes
, with pseudo-random values.
•
boolean nextBoolean()
: Returns a pseudo-random
boolean
value with
true
and
false
being
equally probable.
•
void setSeed(long seed)
: Resets the random number generator to generate values using the
value passed as an argument as a starting seed for the algorithm.
To produce a pseudo-random number of a particular type, you just call the appropriate method for a
Ran-
dom
object. You can repeat a sequence of numbers that has been generated by a
Random
object with a given
seed by calling the
setSeed()
method with the original seed value as the argument.
You can give the
Random
class an outing with a simple program that simulates throwing a pair of dice.
The program allows you six throws to try to get a double six.
TRY IT OUT: Using Random Objects
Here's the program:
import java.util.Random;
import java.io.IOException;
public class Dice {
public static void main(String[] args) {
System.out.println("You have six throws of a pair of dice.\n" +
"The objective is to get a double six. Here
goes...\n");
Random diceValues = new Random();
// Random number
generator
String[] goes = {"First", "Second", "Third",
"Fourth", "Fifth", "Sixth"};
int die1 = 0;
// First die value
int die2 = 0;
// Second die
value
