Since Wordpress version 2.x, jQuery is a build-in Javascript library, explicitly include the jQuery library into Wordpress is not necessary.


The jQuery is not working in Wordpress plug-in writing? When you try to test a simple jQuery effect like following


It’s just not working, no alert message box pop up. The same script is working as expected in single HTML page. What’s the heck? Is there any interoperability issues between jQuery and Wordpress?


In Wordpress, the$() syntax is always used by other scripting library, and causing the conflict issue and fail to call the jQuery function. You should use jQuery() instead…


Alternatively, you can use noConflict()


// Use jQuery via $j(...)

P.S jQuery.noConflict();

Never use jQuery handy function $() in Wordpress plugin. You have to use jQuery() or jQuery.noConflict() to work between jQuery and Wordpress.