Example migrated from Codex:

Add Columns

Suppose you have a ‘books’ custom post type and you want to add the publisher and book author to the list of columns.

add_filter('manage_books_posts_columns' , 'book_cpt_columns');

function book_cpt_columns($columns) {
	$new_columns = array(
		'publisher' => __('Publisher', 'ThemeName'),
		'book_author' => __('Book Author', 'ThemeName'),
	);

    return array_merge($columns, $new_columns);
}

Replace Columns

Here’s another example that removes and replaces some of the columns.

add_filter('manage_books_posts_columns' , 'book_cpt_columns');

function book_cpt_columns($columns) {
	unset(
		$columns['author'],
		$columns['comments']
	);

	$new_columns = array(
		'publisher' => __('Publisher', 'ThemeName'),
		'book_author' => __('Book Author', 'ThemeName'),
	);

    return array_merge($columns, $new_columns);
}

Note that unlike an array data type, the unset PHP function accepts arguments in which the last argument should NOT end with a comma.

Hide Columns

Here is an example of how to remove or (hide) columns from Pages / Posts and Custom Post Types without adding any.

You can also add the name of the custom-post type and filter them out in there too… But if you have 5 custom post types you will need five different filters.

Note: Replace the text CUSTOMPOSTTYPE below with the name of your post type.

// Filter pages
add_filter( 'manage_edit-page_columns', 'my_columns_filter',10, 1 );	

// Filter Posts
add_filter( 'manage_edit-post_columns', 'my_columns_filter',10, 1 );

// Custom Post Type
add_filter( 'manage_edit-CUSTOMPOSTTYPE_columns', 'my_columns_filter',10, 1 );

function my_columns_filter( $columns ) {
   unset($columns['author']);
   unset($columns['categories']);
   unset($columns['tags']);
   unset($columns['comments']);
   
   return $columns;
}