How to randomly pick an element from an array

Solution 1:

public static int getRandom(int[] array) {
    int rnd = new Random().nextInt(array.length);
    return array[rnd];
}

Solution 2:

You can use the Random generator to generate a random index and return the element at that index:

//initialization
Random generator = new Random();
int randomIndex = generator.nextInt(myArray.length);
return myArray[randomIndex];

Solution 3:

If you are going to be getting a random element multiple times, you want to make sure your random number generator is initialized only once.

import java.util.Random;

public class RandArray {
    private int[] items = new int[]{1,2,3};

    private Random rand = new Random();

    public int getRandArrayElement(){
        return items[rand.nextInt(items.length)];
    }
}

If you are picking random array elements that need to be unpredictable, you should use java.security.SecureRandom rather than Random. That ensures that if somebody knows the last few picks, they won't have an advantage in guessing the next one.

If you are looking to pick a random number from an Object array using generics, you could define a method for doing so (Source Avinash R in Random element from string array):

import java.util.Random;

public class RandArray {
    private static Random rand = new Random();

    private static <T> T randomFrom(T... items) { 
         return items[rand.nextInt(items.length)]; 
    }
}