Can't use function return value in write context

[Claus Mygind]

I want to test a value of a column to see if it is null, empty or just contains blanks spaces.

And I get the error stated in the title of this thread, when I just want to test the trimmed value like so:

if ( empty(trim($val)) ) {
 

So I it seems I am forced to add a second line to my code like this

$val = trim($val);
if ( empty( $val ) ) {
 

What I don't understand is I can use it in a "switch" command as this code works fine for me.

switch (strlen(trim($val)))
{
 

So here I basically have two "if" commands one where the "trim" function works and one where it does not work.

Is this true? And if so Why?

[Dormilich]

empty() only checks variables as anything else will result in a parse error. In other words, the following will not work: empty(trim($name)).

found in the manual.

besides that, switch() is not a function (not that empty() were a function either …).

[Claus Mygind]

Thanks for the reply and clarification. Of course I was working on a variable "$val"

How disappointing to see this limitation as opposed to the more flexible use of empty() in dBase.

Sorry for stating that empty() was a function, I guess I just thought anything that ended with () was a function. Live and lean.

[Dormilich]

there are even more language constructs that look like a function (include(), require(), echo(), print()).

PS. to be honest, I also looked it up.