Does the '@' symbol have special meaning in Javascript, Coffeescript or Jquery?

Question

I have some code that looks like

self = @

and then later on it's using @someMethodName or self.someMethodName

Does @ have some special meaning?

Osmunda

Is that symbol existed in jquery? – Spiccato

sooo..... is it a Javascript file or a coffeescript file? – Rogovy

@Rogovy it's a coffeescript file, but presumably you could use that if Javascript had defined it. – Osmunda

See https://mcmap.net/q/48458/-what-characters-are-valid-for-javascript-variable-names – Zondra

Answer 1

@ is not a valid character for a javascript identifier. Identifiers may only contain $, _, digits and letters.

In coffeescript, @ means this.

CoffeeScript has a few nice features related to the this keyword. First, CoffeeScript uses the @ symbol as shorthand for this.. For example, @foo is equivalent to this.foo. Second, if you use the @ symbol in the parameters of a function, CoffeeScript will automatically assign those values as properties of the object.

Edit: As far as jQuery is concerned, the same identifier rules as javascript apply since jQuery is just javascript. For other uses of @ in jQuery, see this question or the docs.

Cockleshell

It's worth adding that @foo means this.foo in CoffeeScript. – Deluna

It may also be worth noting that => is pretty freaking confusing when you're trying to read someone else's CoffeeScript, imho. – Olympus

Answer 2

@ is shortcut for this in coffeescript

So

self = @

is coffeescript for:

var self = this;

Rheims

which nowadays, for safety, should be const self = @ ;) – Duke

Answer 3

Since the design of CoffeeScript a couple of years have passed and not everything which was proposed in CoffeeScript made it into ECMA script. Instead of being used as a shortcut for this, it's proposed to be used for decorators.

Emissary