Deciding the 'this' context in Javascript

Asked Nov 01 '16 at 09:48

Active Nov 01 '16 at 09:48

Viewed 29 times

I understand the context of this in a function is decided by the call site or call stack . In below example , even though the call to bar() is made from foo(), Why 'this' inside bar() is not pointing to foo()?

function bar(){
  console.log(this);
 }

function foo()
{
 bar();
}

foo();

asked Nov 01 '16 at 09:48

user2991413

`this` in your example is the global window unless you use `strict` – mplungjan Nov 01 '16 at 09:50
2

@mplungjan: In loose mode. In strict mode it's `undefined`. – T.J. Crowder Nov 01 '16 at 09:51
1

That's because `this` **is not** determined by the call stack. Where did you get that from? `this` is set by using `o.method(arg1, arg2, ...);` syntax *or* by explicitely calling `method.call(...)` *or* `method.apply(...)`. – freakish Nov 01 '16 at 09:52
@T.J.Crowder thanks for the clarification. I never used strict. – mplungjan Nov 01 '16 at 09:53
This might help: http://stackoverflow.com/questions/3127429/how-does-the-this-keyword-work – Rajesh Nov 01 '16 at 09:54

Deciding the 'this' context in Javascript

0 Answers0