document.createElement not working

Question

I am creating a plugin using jQuery library.

Here i am storing String.prototype in a variable then i am using this variable to extend my Sting objec

Answer 1

That is happening because document.createElement uses this inside itself. When you call it like document.createElement() then this is set to document. But, when you save it as a variable, then this is no longer document, it's window.

You need to call it with the context.

var tag = document.createElement;  // you are saving the function, not its context
var btn = tag.call(document, 'button'); // you need to set the context

If your browser supports it, you can also use .bind:

var tag = document.createElement.bind(document);
var btn = tag('button');