Generate random number within range without repeating numbers in javascript [duplicate]

Question

Possible Duplicate:
Generate 8 unique random numbers between 1 and 100
Generate unique number within range (0 - X), keeping a history to prevent duplicates

I need loop that will run 80 times and generate random number between 0-79 but it will not repeat number that has been generated already.
How can I do that?

Answer 1

  for (var i = 0, ar = []; i < 80; i++) {
    ar[i] = i;
  }

  // randomize the array
  ar.sort(function () {
      return Math.random() - 0.5;
  });

// You have array ar with numbers 0 to 79 randomized. Verify
console.log(ar);

// take out elements like this
ar.pop()