帮助正确的php语法

Question

I was working on some php functions and I got confused with php syntax. Here is the function.

Is this correct? to use add_filter inside function_exists check

if ( ! function_exists( 'disable_password_reset' ) ) :
  function disable_password_reset() {
    return false;
  }
  add_filter ( 'allow_password_reset', 'disable_password_reset' );
endif;

or this one is correct, to use add_filter outside function_exists check

if ( ! function_exists( 'disable_password_reset' ) ) :
  function disable_password_reset() {
    return false;
  }
endif;
add_filter ( 'allow_password_reset', 'disable_password_reset' );

I was working on Wordpress if that matters.

Answer 1

What you are trying to do is:

• Check if function disable_password_reset() exists, and if not, create it.
• Hook disable_password_reset() to a Wordpress filter.

If you do this:

if ( ! function_exists( 'disable_password_reset' ) ) :
  function disable_password_reset() {
    return false;
  }
  add_filter ( 'allow_password_reset', 'disable_password_reset' );
endif;

then add_filter ( 'allow_password_reset', 'disable_password_reset' ); will not be executed if disable_password_reset() already exists. If you don't want that, then you should call add_filter() outside the if block, as in your second example.