Can't use method return value in write context

Question

I would think the following piece of code should work, but it doesn\'t (Edited: Now works in PHP 5.5+):

if (!empty($r->getError()))
         


        

Answer 1

I'm not sure if this would be a common mistake, but if you do something like:

$var = 'value' .= 'value2';

this will also produce the same error

Can't use method return value in write context

You can't have an = and a .= in the same statement. You can use one or the other, but not both.

Note, I understand this is unrelated to the actual code in the question, however this question is the top result when searching for the error message, so I wanted to post it here for completeness.