Welcome to another quick article in the WordPress Development Tips Series.

During the development of my plugins I discover quite a few tips and tricks along the way. In this series I try to share the most important or the ones I feel lack the most documentation.

This tip involves how to create a tag via PHP and assign it to a post.

The code is quite simple, and uses just a single WordPress function, already included in the WordPress code.

The function to use is named wp_set_object_terms, and the usage is as follows:

wp_set_object_terms( $postid, $newtagarray, ‘post_tag’, true );

Example:

wp_set_object_terms( 1, array(‘my new tag’), ‘post_tag’, true );

The code in the example will create (if it doesn’t already exist) a tag named “my new tag”, and assign it to post 1.