Where Do I Add Functions in WordPress?

In WordPress, you can add functions in the following locations:

The Functions.php file

The wp-config.php file

The wp-includes/functions.php file

The wp-admin/includes/functions.php file

The functions.php file is the primary location for functions in WordPress. Functions in this file are called from within the WordPress core code. Functions in the wp-config.php file are called automatically when WordPress is installed and when you create a new WordPress site.

Functions in the wp-includes/functions.php file are called by WordPress when it encounters a function name that is not found in the other files. Functions in the wp-admin/includes/functions.php file are called by WordPress when you use the WordPress admin panel.

When you add a function to a file, you should include the following information in the function:

The function name

The function description

The function parameters

The return type

The function signature

The function copyright

The function license

The function dependencies

If you want to use a function in your WordPress site, you need to include the function in one of the aforementioned files and then include the appropriate WordPress code to call the function.