WordPress and jQuery issues

First, I don’t remember where I found this along the way, but this is a smart and efficient way to include jQuery in your WordPress themes. Just add this to your theme’s functions.php file:

add_action( ‘init’, ‘jquery_register’ );
add_filter( ‘script_loader_src’, ‘jquery_unversion’ );

function jquery_register() {

if ( !is_admin() ) {
wp_deregister_script( ‘jquery’ );
wp_register_script( ‘jquery’, ( ‘http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js’ ), false, ‘1.x’, false );
wp_enqueue_script( ‘jquery’ );

// remove version tag to improve cache compatibility
function jquery_unversion( $src ) {

if( strpos( $src, ‘ajax.googleapis.com’ ) )
$src = remove_query_arg( ‘ver’, $src );

return $src;

Now, the issue I have been having is that when I try to add your own jQuery scripts or functions in your theme’s header.php file, I always get this error:

“$ is not a function”

What?  Yes it is, dammit!

Turns out WordPress has reserved the $ character, so you have to rename all occurence of $ to ‘jQuery’.  Example:



Hope that saves someone the hours of frustration I have had with this.

About Will Chatham

Will Chatham is an Information Security Analyst, OSCP, Ethical Hacker, and Penetration Tester at a federal data center in Asheville, NC. Since Netscape 2.0, he has worked in a wide array of environments including non-profit, corporate, small business, and government. His varied background, from developer to search engine optimizer to security professional, has helped him build a wide range of skills that help those with whom he works and teaches.
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