Wordpress admin - How add custom column in post listing table?

- If you want to add custom column in wordpress admin all post listting, then you just need to add some function on functions.php file.

- Here I try to explain with one example like if you want to add Post ID on admin post listing page.

- Example:

File: wp-content/yourtheme/functions.php

//BELOW FUNCTION FOR DISPLAY HEADER TITLE
add_filter('manage_posts_columns', 'columns_header');

function columns_header('$default') {
 $default['post_id'] = 'Post ID';
 return $default;
}


//BELOW FUNCTION FOR DISPLAY VALUE ON THAT COLUMN

add_action('manage_posts_custom_column', 'columns_content', 10, 2);

function columns_content($column_name, $post_id) {
 if($column_name == 'post_id') {
  echo $post_id;
 }
}

Enjoy!