JavaScript Semantics Confusion

I think you're right. When you are creating a "function" via jQuery, that is actually a method. I think it's because jQuery itself is a giant function. Take a look at the first line of code here http://code.jquery.com/jquery-latest.js

Hi John,

I tend to use the terms interchangeably as in most, if not all cases they're identical in meaning.

I found a stackoverflow that discusses it more, note the replies to the answer on how the definitions slightly change language to language. And I don't think this definition helps either as I'll to try explain.

You can do some pretty crazy-cool things in JavaScript like passing functions around from the global scope in to an object and vice versa. The key with JavaScript is scope of execution of the function.

For example when you define a function like this.

function hello() {
  alert("Hi");
}

//Which means I can call
window.hello();

This function is now a method on window :) Any function defined in the global scope (in browsers) gets bound to the window. Whilst we haven't implicitly passed in window we can access it and all the variables within that scope. this within the context of the hello function is the window.

function hello() {
  console.log(this); //logs out the window.
}

As for jQuery itself, Eric pointed out there's a function declared on the first line, and if you look at the end it executes itself passing in window as a variable. So you could say that this is a method (in the definition from Stack Overflow) since it's function been explicitly called with the object that's calling it has been passed in, window. For more info on self-executing anonymous functions check out this blog post but you can never call it again directly but it binds the jQuery functionality to window.jQuery / window.$ near the end.

// Expose jQuery to the global object
window.jQuery = window.$ = jQuery;

/Me takes a breath

So when you call jQuery("css selector string") or $("css selector string") you're calling the jQuery method on window which is a function defined in a self-executing anonymous function.

So I find that definition proposed on StackOverflow confusing.

To be honest I wouldn't get too hung up on the definitions. Scope is what you should be focusing on not if this is strictly a method or a function, by some definition, either way they get called the same way. The context of this within the method/function is key.

In your day to day developer life if someone says called the blah function rather than blah method there is no issue, people understand these terms as interchangeable.

Eventually you'll be writing code that doesn't pollute the the global scope unnecessarily . CoffeeScript does this straight out of the box wrapping any of your code in a self-executing anonymous function when it's compiled down to JavaScript.

Let me know if I've made it any clearer or worse :)

Regards Andrew

Totally cleared it up Andrew. Thank you so much for the thorough response.

Happy Holidays! John

Great response @Andrew, that's a great little lesson learned ;-) there can definitely be confusing terms used quite a lot and it really helps to have a clear definition like you have given.