Random probability (Customizing random function)

Processing Coding Questions
5

Thanks for the link.
The function used on the referred page is:

function rollDice(N, S):
    # Sum of N dice each of which goes from 0 to S
    value = 0
    for 0 ≤ i < N:
        value += random(S+1)
    return value

I assume that an equivalent Processing code would be something like this:

float value;

void rollDice(int N, float S) {
  value = 0;
  for (int i = 0; i < N; i++) {
    value += random(S+1);  
  }
}

I’ve experimented some different codes to implement this function,
But it still doesn’t make sense to me.