Want to produce random numbers between 1-45 without repetition

Question

I have come across a very strange problem. I have tried to find its solution but in vain. My problem is that I want to create a random number between 1-45 and I don\'t want tha

Answer 1

What you really want is to create a set of numbers in a given range and to randomly remove one of the numbers until the set is empty.

Here is a function which generates another function which does exactly that:

function generateRandomRangeSet(beg, end) {
  var numbers = []; // Create an array in range [beg, end].
  for (var i=beg; i<=end; i++) { numbers.push(i); }
  return function() {
    if (numbers.length < 1) { throw new Error('no more numbers'); }
    var i=Math.floor(Math.random()*numbers.length), number=numbers[i];
    numbers.splice(i, 1); // Return and remove a random element of the array.
    return number;
  }
}

var r = generateRandomRangeSet(1, 45);
r(); // => 9
r(); // => 24
r(); // => 7 ... for each number [1, 45] then ...
r(); // Error: no more numbers