Function.bind vs Closure in [removed] how to choose?

Question

As said here:

http://jqfundamentals.com/book/index.html

Closures can also be used to resolve issues with the this keyword, which is unique t

Answer 1

Take a look at this line in the example in the link above

console.log(self.myName, this.myName);

(with self = this; a couple of lines above). The closure defined outerFunction method, exists in a different scope that is why it has a different this value from the outerObj object. (self.myName!=this.myName)

Scope traversal means, when you are reaching to grab a value (variable,object) that exists in a different scope, therefore additional overhead is added (code becomes slower to execute).

Using bind, you 're calling a function with an existing scope, so that scope traversal does not take place.

Answer 2

What it's referring to are things like this

obj.doSomething = function() {
  var that = this;
  setTimeout(function() {
    // this is the window
    // that is the obj
    that.doSomethingElse();
  }, 50);
};

vs

obj.doSomething = function() {
  setTimeout((function() {
    // this is the obj
    this.doSomethingElse();
  }).bind(this), 50);
};

Benchmark. No noticable difference in chrome.