Random Number Duplicates

Yeah - that would work. Alternatively, generate two random numbers and perform some mathematical function with them; that makes the chances of two being the same smaller.

Alternatively, you can generate two random numbers:

Random rNumber = new Random();
int first = rNumber.nextInt(10);
int second = rNumber.nextInt(10);
if (first == second) {
  //do something to break the equality
  first++;
  second--;
}

I don't know what your requirement is or why two numbers being the same is a problem. But there's simple ways round that, as above.

Steve.

Hi Steve,

Thanks for the answer. Yes I am aware of the fact that I am unable to influence the random generation of numbers but what if after we generate the second number then compare it to the previous one. If they are the same then maybe call for another generated number until we get a unique number.

That is what I practically had in mind,

It is a random number generator. By definition, the production of the next number is not influenced by the value of any other number, including the previous one.

Steve.

Surprising how often it occurs - this logs "Matched!" when the next number is the same as the last.

        int lastRandom = 0;

        Random randomGenerator = new Random();
        for(int i = 0; i < 1000; i++){
            int nextRandom = randomGenerator.nextInt(100);
            if(lastRandom == nextRandom){
                System.out.println("Matched!");
                // generate another number
                nextRandom = randomGenerator.nextInt(100);
                // or just increment
                nextRandom++;
            }
            lastRandom = nextRandom;
            System.out.printf("%s ", lastRandom);
        }