I'm writing a utility file and I've gotten some examples from online and this a form of writing the utility I've come across:
$.util = $.extend($.util || {}, { //functions here... }); and so I think I understand what it's doing. It allows me to call $.util.function() somewhere else, however when I remove the . in front of the $ the code breaks. What does this notation mean? What's the difference between $. and $?
$.util = something means "assign something to property util of object $".
$util = something means "assign something to variable $util"
Similarly, $.extend is "get value of property extend of object $" (which is a function in this exact scenario) and $extend is "get value of variable $extend"
$ onto any variable would automatically make it jQuery. I'm not sure why I thought that but that makes sense. Thank you!If you're using jQuery, $ is just a variable contaning the jQuery object. So by writing $., you're essentially accessing jQuery properties and functions. Instead of $, you could also write jQuery and it should work the same way.
There's no special meaning to the $ character in JavaScript other than that. It acts like any other character, so $util is just a variable name.
jQuery is an object that is assigned to both jQuery and $ on the window
It has methods that act on collections of elements eg $('.some-element').someMethod() and static methods that are just attached to the jQuery object but don't modify a collection, They are just normal function attached to the jQuery object to prevent exposing too many functions to the global context.
$. - allows you to proceed to $ (jQuery) object property or method directly$ - usually used as shortcut for invoking jQuery objectWhilst prefixing anything with $ won't make it jQueryable bec. this character can be used in variable name along with others (e.g. what is not applicable for PHP).
Consider jQuery as a big class woth a lot of static functions and constructs.
The right way for calling any of its functions should be jQuery.someFunc() for static functions and var obj = jQuery('css selectors') for creating an object for HTML objects and then executing functions on that object.
Now for easier coding, jQuery added $ as an alias for jQuery. It's nothing more than an alias.
Try this code:
<script type="text/javascript"> document.write('(jQuery === $) is ' + (jQuery === $) + '<br />'); document.write('typeof(jQuery) = ' + typeof(jQuery) + '<br />'); </script> You will see:
(jQuery === $) is true
typeof(jQuery) = function
So jQuery is a function with a bunch of extra properties and functions attached to it.
If you're coming from a strongly-typed language background, the concept of attaching properties and methods to a function might seem strange, but you can do it in javascript.
$as a synonym forjQuerythen it becomes clear why "jQueryutil" doesn't work.