Can Someone Explain What The Syntax Means When Defining A Jquery Plugin?

I am reading up on creating custom jQuery plugins and am a little confused as to the meaning of the following syntax: (function($){ $.fn.truncate = function() { ret

Solution 1:

The following parameters with jQuery are just executing the anonymous function and passing in jQuery as the $ parameter. This ensures that $ = jQuery just incase window.$ doesn't equal jQuery.

Here is a rewrite of the code that might make more sense:

functionmyFunc($) {   
 $.fn.truncate = function() {   
    returnthis.each(function() {   
 });   
}

myFunc(jQuery);

Solution 2:

The surrounding parentheses create an anonymous function to which the $ symbol references the global jQuery object.

$.fn.truncate - This means that you are extending the jQuery object to include a new function called truncate. Usage$( '#someElement' ).truncate();

Solution 3:

It is not safe to assume that $ is owned by the jQuery library. Some other javascript libraries/users may/do use that identifier for other purposes. However, jQuery is always the jQuery library (barring any evildoers).

This anonymous function handily and safely exposes the $ shortcut as jQuery by making it a local parameter to the anonymous function. Since parameters will override any globals only for the scope of a function this will not affect any other user/library code outside of it.

Finally, where the anonymous function is executed jQuery is passed in as the first paramter to fill $.

So when boiled down, this is just a shortcut taken by plugin developers so that they can safely and reliably use $; if you don't mind using jQuery everywhere instead then this is totally optional.