closure/asynchrony/hoisting

gistfile1.js

// 1 (closures/asyncrony)
function sleepsort (input) {
  for(var i=0; i<input.length; i++) {
    setTimeout(function () {
      console.log(i);
    }, i * 1000);
    
    console.log('iterated');
  }
};

sleepsort([2, 1, 3])

// show that "iterated" is printed before any of the array elements are

// 2
function sleepsort (input) {
  for(var i=0; i<input.length; i++) {
    var j = i; // explain why this doesn't work (hoisting)
    
    setTimeout(function () {
      console.log(j);
    }, j * 1000);
  }
};

// 3 explain why this works (functions create scope)
function sleepsort (input) {
  for(var i=0; i<input.length; i++) {
    (function (j) {
      setTimeout(function () {
        console.log(j);
      }, j * 1000);
    })(i);
  }
};