How can I use `json_last_error()` to handle JSON decoding failures?

When decoding JSON using `json_decode()`, check the return value of `json_last_error()` after the call. If it's not `JSON_ERROR_NONE`, it indicates an error. You can then use a series of `if` or `switch` statements to determine the error type based on the error code and take appropriate action, such as logging the error or displaying a user-friendly message.