[Function] Output comma-separated top-level categories of the current post

This members-only tutorial provides the steps to define a custom function in WordPress that outputs categories of the current post that are not children of other categories - separated by commas.

Ex.:

For a post that belong to these categories:

the function will output:

Notice how "Child Category 1" does not get included since it is a child category.

If using Oxygen, add a text component like Text or Heading. Double click the text, click Insert Data button in the top toolbar, then PHP Function Return value and put in the Function Name, wpdd_post_categories_toplevel and then click INSERT.

Step 1

Install and activate Code Snippets plugin.

Go to Snippets > Add New.

Title: [Function] Output comma-separated top-level categories of the current post

Code: