Question

I am getting the error:

Function name must be a string on this code:

$profile_data = $user_data('first_name','last_name','email');

Any ideas why this could be?

Answer 1

While you can use variables as function-names, to do so requires the variable to be a string.

The variable $user_data sounds more like an array, or even possibly an object. If this is true, you will receive the error specified. Per the comment from @Jon, it could also be possible that user_data() is a method and the $ is a typo.

If none-of-the-above helps, please all relevant code, specifically the creation of the $user_data variable (or a var_dump($user_data) output).