Javascript generate random unique number every time

Question

Ok so i need to create four randomly generated numbers between 1-10 and they cannot be the same. so my thought is to add each number to an array but how can I check to see i

Answer 1

var a = [];
for (var i = 0; i < 5; i++) {
  var r = Math.floor(Math.random()*10) + 1;
  if(!(r in a))
    a.push(r);
  else
    i--;
}

That'll do it for you. But be careful. If you make the number of random numbers generated greater than the may number (10) you'll hit an infinite loop.