Applying a Function to Null in Javascript

Question

Why does the following work:

function sum(a,b) { return a + b; }
var result = sum.call(null,3,4);     // 7

Why is result defined? I am invo

Answer 1

Its not. NULL in this case specifies to what object the this keyword is bound to. In your method, by setting it to NULL it will either not have a this variable binding or it will be bound to the function itself or the window.

Since you're not using any variables or functions that are accessed via this, then there's no need to use the call method ... you can just use sum(3,4)