How to generate 6 different random numbers in java

Question

I want to generate 6 different random numbers by using Math.random and store them into an array. How can I make sure that they are different? I know I need to use for-loop t

Answer 1

You can use a Set.

Set s = new HashSet<>();
while(s.size() != 6){
   s.add(1 + (int) (Math.random() * 49));
}

Integer[] arr = s.toArray(new Integer[s.size()]);

This is enough to do this in your case because the number of distinct random numbers is relatively small compared to the size of the range you generate them.

Otherwise I would go with @JBNizet approach.