Is it possible to restrict the scope of a javascript function?

Question

Suppose I have a variables in the global scope.

Suppose I wish to define a function which I can guarantee will not have access to this variable, is there a

Answer 1

You can't restrict the scope of a Function using the "call" or "apply" methods, but you can use a simple trick using "eval" and scoping to essentially hide any specific global variables from the function to be called.

The reason for this is because the function has access to the "global" variables that are declared at the scope that the function itself what declared. So, by copying the code for the method and injecting it in eval, you can essentially change the global scope of the function you are looking to call. The end result is essentially being able to somewhat sandbox a piece of javascript code.

Here's a full code example:

The code that gets eval'd looks like this:

var window = {};
var document = {};
(function displayTitle()
{
    alert(document.title);
})();