gistfile1.md

Callbacks

Callbacks are functions that are called within another function. Because functions in javascript can be passed around through variables, this makes it pretty painless.

Setting it up

function myFn(callbackFn) {
    if (callbackFn) {
        (callbackFn());
    }
}

Now we have a function that's ready to take a function as a parameter and call it. We can do many things to this, but lets start off simple.

myFn(function() {
    alert('hi');
});

This will call the function and pass an anonymous function as the call back. When it's executed within myFn() it will alert "hi".

Do I have to use an anonymous function?

No. You can pass function names as well.

function myOtherFn() {
    alert('hello');
}
myFn(myOtherFn);

Or even

var myOtroFn = function() {
    alert('ohla');
};
myFn(myOtroFn);