Question

When using add_action, is it better to write:

add_action('blah', 'my_function');
function my_function() { return $something; }

or

function my_function() { return $something; }
add_action('blah', 'my_function');

?

Answer 1

It’s purely a stylistic choice, both behave in exactly the same way.

Personally I prefer

add_action('blah', 'my_function');
function my_function() { return $something; }

as I feel it’s easier to identify the hooks when reading through code. If the function is particularly long then it may not be immediately apparent that it’s being hooked in.

For reference, the same question has been asked on quora – http://www.quora.com/WordPress/In-WordPress-is-it-best-practice-to-add_action-before-or-after-your-custom-function