numberposts, showposts, posts_per_page. What's the difference?

Question

Every time I see different answer.

Can anyone give me a good reliable answer on the difference between numberposts, showposts, posts_per_page when querying posts?

Answer 1

They are all the same and does exactly the same thing. Usage are slightly different though

• numberposts, posts_per_page and showposts are all valid in get_posts(). numberposts is set to posts_per_page before being passed to WP_Query. Check the source code

  if ( ! empty($r['numberposts']) && empty($r['posts_per_page']) )
      $r['posts_per_page'] = $r['numberposts'];
  

• posts_per_page and showposts are all valid in WP_Query but numberposts not. If showposts is used, it is set to posts_per_page in the WP_Query class. See the source code

  if ( isset($q['showposts']) && $q['showposts'] ) {
      $q['showposts'] = (int) $q['showposts'];
      $q['posts_per_page'] = $q['showposts'];
  }
  

Although the codex says showposts is depreciated, there is still no depreciation notice in core.It was however replaced in favor of posts_per_page.

To answer your question, posts_per_page is probably the best to use as numberposts and showposts are being set to posts_per_page in the WP_Query class