Fun excercise I did with a tech co-founder

fun-excercise.js

/* 
Task:
----------------------------------------------------
Fill the array 'randomNumbers' with 64 random numbers. 
----------------------------------------------------

Requirements:
* You must use the provided getRandomNumber function.
* Make sure that there are no duplicate numbers in the array.
* Try to keep the running time reasonable!

*/

// You can't change this function
function getRandomNumber(callback) {
  var random = Math.floor( Math.random() * 70 );
  setTimeout( function(){ callback(random); }, 1000);
}

var randomNumbers = [];

// Start your code below here
// -----------------------------------

randomNumbers.isAlreadyHere = function isAlreadyHere(someNumber) {
  var length = randomNumbers.length
    , result = false;
  for (var spot = 0; spot < length; spot++) {
    if (randomNumbers[spot] === someNumber) {
      result = true;
    }
  }
  return result;
};

for (var round = 0; round < 65; round++) {
  getRandomNumber(function getRandCallback(random) {
    while (randomNumbers.isAlreadyHere(random)) {
      random++;
      random %= 70;
    }
    randomNumbers[randomNumbers.length] = random;
  });
}