What is the purpose of a self executing function in javascript?

Question

In javascript, when would you want to use this:

(function(){
    //Bunch of code...
})();

over this:

//Bunch of code...
         


        

Answer 1

(function(){
    var foo = {
        name: 'bob'
    };
    console.log(foo.name); // bob
})();
console.log(foo.name); // Reference error

Actually, the above function will be treated as function expression without a name.

The main purpose of wrapping a function with close and open parenthesis is to avoid polluting the global space.

The variables and functions inside the function expression became private (i.e) they will not be available outside of the function.