Generate a random even number inside a range?

Question

Here's the format I'm following:

 int randomNum = rand.nextInt((max - min) + 1) + min;

So here's my code. I'm trying to get a random even number between 1 and 100:

 Random rand = new Random(); 
 int randomNum = rand.nextInt((100 - 2) + 1) + 2;

I saw one solution is to multiply the number by 2, but that breaches the intended range.

I thought of doing a bunch of if statements to solve this, but it seems overly complex. Is there a relatively simple solution?

Answer 1

Just generate a number from 0 to 49 and then multiply it by 2.

Random rand = new Random(); 
int randomNum = rand.nextInt(100/2) *2;

To do it in a range just add the range in:

int randomNum = startOfRange+rand.nextInt((endOfRange-startOfRange)/2) *2;

Note that startOfRange should be an even number or converted into an even number.

Answer 2

Here´s a tiny example on how to do it

static Random rand = new Random();

public static void main(String[] args) {
    for(int i = 0;i<100;++i)
        System.out.println(generateEvenNumber(0, 100));

}

private static int generateEvenNumber(int min, int max) {
    min = min % 2 == 1 ? min + 1 : min; // If min is odd, add one to make sure the integer division can´t create a number smaller min;
    max = max % 2 == 1 ? max - 1 : max; // If max is odd, subtract one to make sure the integer division can´t create a number greater max;
    int randomNum = ((rand.nextInt((max-min))+min)+1)/2; // Divide both by 2 to ensure the range
    return randomNum *2; // multiply by 2 to make the number even
}