Unexpected T_CONCAT_EQUAL

Question

I get an unexpected T_CONCAT_EQUAL error in a line like this:

$arg1 .= "arg2".$arg3."arg4";

I am using PHP5. I could just do the following:

$arg1 = $arg1."arg2".$arg3."arg4";

but I would like to know what happens first. Any ideas?

Thanks Sweeney

Answer 1

This will happen when $ arg1 is undefined (it doesn't matter, it has never been set.)

Answer 2

So the most accurate reason is because the above line of code is:

$arg1 .= "arg2".$arg3."arg4";

in my source was as follows:

arg1 .= "arg2".$arg3."arg4";

There is no $ value in arg1. I do not know why the interpreter did not catch it first, but whatever it is. Thanks for the contribution of Jeremy and Bailey - this led me to the problem.

Answer 3

, .