Question

I’m learning javascript and one thing I keep hearing is “functions are objects”. Can you provide some examples for me to better understand this concept?

Answer 1

Sure. Here’s some example code:

function Hello() {
    alert(Hello.world);
}

Hello.sayHello = Hello;
Hello.world = 'Hello, world!';

Hello.sayHello.sayHello.sayHello.sayHello.sayHello();

Here’s proof that it works, too.

Notice how you can assign properties to the function, and assign it to itself and refer to it recursively. It’s an object, like most other things in JavaScript, and you can do anything with it. If you’ve seen prototype inheritance before:

Function.prototype.alert = function() {
    alert(this.apply(null, arguments));
};

function add(a, b) {
    return a + b;
}

add.alert(1, 2); // Alerts 3

There’s a lot here – a function literal, which is a function without a name in essence; prototypical inheritance; methods on functions; dynamic arguments; a function as this.