how to generate random number from array

Question

How to generate random number from an array? and not from a range.

int n [] = {1,7,3,5,8,10,33,12,18}

possible duplicate of How to generate a random number with Java from given list of numbers — mmmmmm
– mmmmmm, Commented May 8, 2012 at 14:16
It isn't clear what this question is asking. Do you want to randomly pick a number from this array, and then return that number? — Anderson Green
– Anderson Green, Commented Mar 7, 2013 at 21:19

Barthelemy · Accepted Answer · 2010-03-27 00:24:35Z

16

import java.util.Random;

...

Random random = new Random();
System.out.println(n[random.nextInt(n.length)]);

answered Mar 27, 2010 at 0:24

Barthelemy

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1 Comment

Note that you should cache the Random instance in a field instead of creating a new instance each time you need a random number.

kbenson · Accepted Answer · 2010-03-27 00:27:03Z

0

In general terms, get a random integer ranging from a minimum of 0 to a maximum of the array length -1, and use that as the array index.

answered Mar 27, 2010 at 0:27

kbenson

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