[Javascript] Function Scope

We have the code like:

var = [numbers];  for (var in numbers) {     setTimeout(function() {Console.log (numbers[i]);      0);} // 3 // 3 // 3

Note:

1. function block doesn ' t create scope!

2. setTimeout function Runafter all the other code finished.

Therefore, before SetTimeout get run, for block already exec 3 times and I is set to 2.

Once SetTimeout get running, it prints out numbers[i] which is 3.

Now, we have the code to:

var = [numbers];  for (var i  inch   numbers) {   (function() {       var j = i;        SetTimeout (function() {           console.log (numbers[j]);})    }) ();} // 1 // 2 // 3

Note:

1. function does create new scope.

2. The (function () {}) () Run immedatly.

3. (function () {}) inside for block actually is closure which does remeber the local var value var j).

[Javascript] Function Scope