Shortcuts for jQuery’s ready() method

The third option is not a shortcut for .ready() (or jQuery related really), the self invoke runs immediately (as soon as it appears in the code), this is probably the shortcut you’re thinking of though:

$(function(){
  alert("I'm a ready shortcut");
});

Passing a function into $(func) is a shortcut for $(document).ready(func);. The no-conflict version would look like this:

jQuery(function($) {
  //$ is jQuery
});