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

Given your simple question: "In javascript, when would you want to use this:..."

I like @ken_browning and @sean_holding's answers, but here's another use-case that I don't see mentioned:

let red_tree = new Node(10);

(async function () {
    for (let i = 0; i < 1000; i++) {
        await red_tree.insert(i);
    }
})();

console.log('----->red_tree.printInOrder():', red_tree.printInOrder());

where Node.insert is some asynchronous action.

I can't just call await without the async keyword at the declaration of my function, and i don't need a named function for later use, but need to await that insert call or i need some other richer features (who knows?).