That's because you're not using add_action
correctly, what you've written is functionally the same as this:
function xyz_footer_print() {
echo 'footer script here';
}
$value = xyz_footer_print();
add_action( 'wp_footer', $value );
xyz_footer_print()
immediately runs the function and returns nothing. As a result your add_action
call says that on the wp_footer
even, do nothing.
So you actually have 2 problems not 1, and if you check your PHP error log or install a tool such as query monitor/debug bar you'd see the warning/notice.
Instead actions always take the form:
add_action( 'action name', 'callable type value, aka the name of function to run when the action happens' );
That should give you enough information to fix this, but, it's the wrong way to put javascript in your footer. You should instead use a JS file and enqueue it the way webelaine suggested.