April 2018
Beginner
536 pages
13h 21m
English
The value of this inside a function depends on how the function is invoked. If we simply invoke a function in non-strict mode, the value of this within the function will point to the global object as follows:
function f1() {
return this;
}
f1() === window; // true
However, if we invoke a function in strict mode, the value of this within the function's body will point to undefined as follows:
console.log(this); // global (window)
function f2() {
"use strict";
return this; // undefined
}
console.log(f2()); // undefined
console.log(this); // window