php returning mixed data types - good or bad

Question

When returning values in php, is it considered good or bad practice to return mixed data types. I\'m working on a project where I am constantly faced with methods that return a

Answer 1

This answer needs an update. There is a better solution as of PHP 7.1:

This is what I do if I want to return a string but it might be null:

    function myFunction(): ?string{
        //do things here and return string or null
    }

The ? before the string essentially means null or string as the return type. This allows you to have a limited return type but still allows null. This works for all types.

You can read more here PHP Manual - returning values