penguinCoder

Just for FYI, computers cannot generate actual random numbers. They are machines, and they do what they are told; and therefore cannot just choose a number at random. Mathematicians would call the process this process 'psuedo-random' number generation, but I didn't feel that made a good title so, whatever.. Just covering all the bases.

First you will have to import the library:

Java Code:

import java.util.Random;

Next, you create a random number generator; most of the time is it made a static data member so that it can be shared by all the methods:

Java Code:

private static Random generator;

The keyword 'generator' is just the variable name, and can be changed to whatever you see fit; but it is good practice to choose descriptive variable names.

After that you will have to initialize your new generator:

Java Code:

generator = new Random();

This can be done at the same time as when 'generator' is created, like:

Java Code:

private static Random generator = new Random();

To generate one random integer:

Java Code:

int nextInt;
nextInt = generator.nextInt();

To generate one random integer from 0 up to, but NOT including MAX:

Java Code:

final int MAX = 24;
int nextInt;
nextInt = generator.nextInt(MAX);

To generate one random integer between 1 through MAX:

Java Code:

final int MAX = 24;
int nextInt;
nextInt = generator.nextInt(MAX) +1;

To generate one real number from 0 up to, but NOT including 1:

Java Code:

double nextDouble;
nextDouble = generator.nextDouble();

To generate one real number from 0 up to, but NOT including MAX:

Java Code:

final double MAX = 100;
double nextDouble;
nextDouble = generator.nextDouble() * MAX;