I already wrote a random generator which take arguments a and b, where a is minimun and b is maximum value, like this randomGenerator(int a, int b)

What I want to do next is: Using a loop, then generate unique number from a to b. Example:

I want to have 8 unique numbers,
int a = 1;
int b = 10;
int value;

If I do the loop, there is a high % that same number will appear more than once. Any idea how to do it?

My own way is:

while(int i <= 8){
  randomGenerator(a,b);
  // if value is not in array, then insert into array
}

I am stuck at the comment part. Is there any way to check if a variable is exists in an array?