Getting random numbers in Java

java random
Unknown user picture Unknown user · May 4, 2011 · Viewed 2.3M times · Source

I would like to get a random value between 1 to 50 in Java.

How may I do that with the help of Math.random();?

How do I bound the values that Math.random() returns?

Answer

nyanev picture nyanev · May 4, 2011

The first solution is to use the java.util.Random class:

import java.util.Random;

Random rand = new Random();

// Obtain a number between [0 - 49].
int n = rand.nextInt(50);

// Add 1 to the result to get a number from the required range
// (i.e., [1 - 50]).
n += 1;

Another solution is using Math.random():

double random = Math.random() * 49 + 1;

or

int random = (int)(Math.random() * 50 + 1);

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