Does console.log treat 'this' differently?

console.log, javascript

Solution

The reason that you get an object and not a string as the output of your function is that by default javascript 'this' object is always forced to be an object.

If you however use javascript in a strict format with 'use strict' then this is disabled and you can get the result that you would expect.

// wrapped in a function to allow copy paste into console
(function() {
   'use strict';

   (function(){ console.log(this); }).apply(String("hello")); 
})();

A more thorough explanation about 'strict mode' and why it removes the boxing of this into an object can be found on the mozilla site here

Problem

Why does the following statement: ``` (function(){ console.log(this); }).apply(String("hello")); ``` display the following output ``` String {0: "h", 1: "e", 2: "l", 3: "l", 4: "o", length: 5} ``` and not a simple: ``` hello ``` Is this behavior built-in to the interpreter or is there a way to detect the type of reference passed?

Original source