Dollar sign $ in jQuery

The magic of the $

 In jQuery, the $ character is the shortcut to the jQuery factory, meaning that it provides access to the jQuery object and all of the power that jQuery offers. You can use the $ to access global objects and functions, and, more commonly, elements and other components in the DOM.

The first operation you'll typically perform in any page that uses jQuery is to register a document.ready event handler. The document.readyevent handler executes after everything on the page has loaded, ensuring that the entire DOM is now in memory, and the jQuery library is now available.

There are a couple of ways to register this event handler. The first is to access the document object in jQuery, and register an event handler with the jQuery ready event.

$(document).ready(function() {
 // code here
});

Because registering an event handler with jQuery is so common, jQuery provides a shortcut. Simply passing a function into the constructor will register that function as the event handler for document.load.

$(function() {
 // code here
});

Both of the code blocks above are semantically identical.