wp hooks and filters example

<?php 
//action
do_action('tagname');
do_action('tagname2', 'asdasd', 2);

add_action('tagname', 'callback_function');
add_action('tagname2', 'callback_function2', 10, 2);

function callback_function()
{
	# code...
}

function callback_function2(a, b)
{
	# code...
}




class TestClass{
	function __construct(){
		add_action('tagname', array($this, 'callback_function'));
		add_action('tagname2', array($this, 'callback_function2'), 10, 2);

		$t2 = new TestClass2();
		add_filter('tagname', array($t2, 'callback_function3'), 10, 3);
	}

	public function callback_function()
	{
		# code...
		//
	}

	public function callback_function2(a, b)
	{
		# code...
	}

	
}

class TestClass2{
	public function callback_function3(x, y, x){

		x = 2+y*z;

		return x;
	}
}

$object = new TestClass();

//filter

$a = apply_filders('mytag', 2 , 'b', 10);



//add_filter('mytag', 'callback_function', 10, 3);

function callback_function(x, y, x){

	x = 2+y*z;

	return x;
}