How to pass parameter in wordpress url?

How do I pass an additional parameter to apply_filters() in WordPress?

• The second parameter, $argument, does not seem to be passed to the function hooking the filter.  I expected "Hello World!" would be displayed but only "Hello" was displayed. <?php /* Plugin Name: Apply Filters Demo */ add_action('admin_init', 'apply_filters_demo'); function apply_filters_demo() { $string = 'Hello'; $argument = 'World!'; $string = apply_filters( 'my_filter_hook', $string, $argument ); echo '<div class="updated">' . $string . '</div>'; } add_action('my_filter_hook', 'apply_filters_myfunc' ); function apply_filters_myfunc($string, $argument='') { return $string . ' ' . $argument; }

• Answer:

  I guess there is a problem with your add_action function. add_action takes 4 variables. The first and second are required. name of the filter, name of the function. priority (when does the function gets fired). Amount of parameters. So the modification must be something like this. add_action('my_filter_hook', 'apply_filters_myfunc' ,10,2); function apply_filters_myfunc($string, $argument='') {     return $string . ' '  . $argument; } Hope this works for you. ----------------------------- http://www.sachingkulkarni.com/