WordPress at a glance
function is not described

Automattic\Jetpack\Autoloader\jp1c37d41437aca3a88a6b698473c4d5c4

Hook_Manager::add_filter() public WC 1.0

Adds a filter to WordPress and registers it internally.

{} It's a method of the class: Hook_Manager{}

No Hooks.

Return

Null. Nothing.

Usage

$Hook_Manager = new Hook_Manager();
$Hook_Manager->add_filter( $tag, $callable, $priority, $accepted_args );
$tag(string) (required)
The name of the filter which is hooked.
$callable(callable) (required)
The function to call.
$priority(int)
Used to specify the priority of the filter.
$accepted_args(int)
Used to specify the number of arguments the callable accepts.

Code of Hook_Manager::add_filter() WC 5.0.0

<?php
public function add_filter( $tag, $callable, $priority = 10, $accepted_args = 1 ) {
	$this->registered_hooks[ $tag ][] = array(
		'priority' => $priority,
		'callable' => $callable,
	);

	add_filter( $tag, $callable, $priority, $accepted_args );
}