jquery anonymous function declaration meanings

Are the following assumptions accurate?

1) execute immediately


2) execute on document ready


3) shorthand for on document ready


4) alternative shorthand for on document ready for avoiding cross script conflicts

(function($) {

Yes your definitions are correct, for the first 3 🙂

Though, unless you need a closure, a statement will execute immediately, no reason to wrap it like #1 has (there are certainly plenty of valid times you need a closure, just noting if you don’t…it’s superfluous).

Number 4 however is not correct, (function($) { })(jQuery); is not tied to any event, it’s just a closure so that $ === jQuery inside of it, so you can use the $ shortcut:

(function($) { 
  //You may use $ here instead of jQuery and it'll work...even if $ means
  //something else outside of this closure, another library shortcut for example

Here’s the #4 you were looking for:

jQuery(function ($) {

It will run on document.ready, within a namespace, and with jQuery defined as $.

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