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

It looks like this question has been answered all ready, but I'll post my input anyway.

I know when I like to use self-executing functions.

var myObject = {
    childObject: new function(){
        // bunch of code
    },
    objVar1: ,
    objVar2: 
}

The function allows me to use some extra code to define the childObjects attributes and properties for cleaner code, such as setting commonly used variables or executing mathematic equations; Oh! or error checking. as opposed to being limited to nested object instantiation syntax of...

object: {
    childObject: {
        childObject: {, , }
    }, 
    objVar1: ,
    objVar2: 
}

Coding in general has a lot of obscure ways of doing a lot of the same things, making you wonder, "Why bother?" But new situations keep popping up where you can no longer rely on basic/core principals alone.