Add PHP Code Without Editing Files

Want to add a code snippet without having to edit your theme’s functions.php file? Use a functionality plugin instead.

Editing your theme’s functions.php file carries the risk of breaking the rest of the code in the file and also opens you to the potential that the code will be lost when you update your theme. Instead, you can safely add code snippets using a plugin.

There are several functionality plugins available in the WordPress.org repository. The instructions below explain how to install and use Code Snippets.

1. Go to Plugins → Add New and install and activate the plugin. This will add a Snippets item to your wp-admin dashboard menu.
2.  Navigate to Snippets → Add New. 
3. Enter a title.
4. Paste or type your code in the Code field
5. Click Save Changes and Activate.