Missing argument 2 for the function in wordpress

Question

I am creating a function in wordpress function.php, but I am getting an error:

Missing argument 2 for get_appcara_child() in C:\wamp\www\appcara\wp-content\themes\appkara\functions.php on line 617

The function is giving the correct output, but I don't know why it is displaying this warning

My function.php is

add_action( 'init', 'get_appcara_child',2 );
function get_appcara_child($post,$parent)
{
    echo $post;

    echo $parent;
}

Calling at page.php

$child= get_appcara_child($post->ID , $post->post_parent);

Answer 1

The format is:

add_action( HOOK, CALLBACK, PRIORITY, NUMBER OF PARAMETERS );

You set the priority to 2 and it should be the parameters ($post,$parent). Correction:

add_action( 'init', 'get_appcara_child', 10, 2 );

PS: 10 is the default priority.