Can't use function return value in write context--huh?

[kurt.krueckeberg]

Can someone explain why this line
$bool = isset($_POST['email']) && !empty(trim($_POST['email']));
causes the error message "Can't use function return value in write
context". trim() returns a string. I test if it is empty. So what is
wrong with that?

[Olaf Schinkel]

ku**************@gmail.com schrieb:

Can someone explain why this line
$bool = isset($_POST['email']) && !empty(trim($_POST['email']));
causes the error message "Can't use function return value in write
context". trim() returns a string. I test if it is empty. So what is
wrong with that?

The functions empty() *only* tests Variables.
All other wil cause an error.

[The Hajj]

On Jul 25, 1:39*pm, [e-mail] wrote:

Can someone explain why this line
$bool = isset($_POST['email']) && !empty(trim($_POST['email']));
causes the error message "Can't use function return value in write
context". trim() returns a string. I test if it is empty. So what is
wrong with that?

not that speed matters but && $_POST['email'] != '' is how I would do
it.

As mentioned above and to quote from php.net "Note: empty() only
checks variables as anything else will result in a parse error. In
other words, the following will not work: empty(trim($name)). "

What I said above is faster than

$email = trim($_POST['email'];

if (... && !empty($email)

[larry]

On Jul 25, 10:39 am, [e-mail] wrote:

Can someone explain why this line
$bool = isset($_POST['email']) && !empty(trim($_POST['email']));
causes the error message "Can't use function return value in write
context". trim() returns a string. I test if it is empty. So what is
wrong with that?)

Your function would fail if 'email' isn't set.

try this:

$bool = !empty( ( isset( $_POST['eamil'] ) ? trim( $_POST['email'] ) :
'' ) );

[Jerry Stuckle]

la***@portcommodore.com wrote:

On Jul 25, 10:39 am, [e-mail] wrote:

>Can someone explain why this line
$bool = isset($_POST['email']) && !empty(trim($_POST['email']));
causes the error message "Can't use function return value in write
context". trim() returns a string. I test if it is empty. So what is
wrong with that?)

Your function would fail if 'email' isn't set.

try this:

$bool = !empty( ( isset( $_POST['eamil'] ) ? trim( $_POST['email'] ) :
'' ) );

Incorrect. That's what isset() tests. If $_POST['email'] is not set,
the rest of the expression is never evaluated.

The others had it correct - empty() only works on variables, not the
results of an expression.

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
js*******@attglobal.net
==================

[kkruecke]

Incorrect. That's what isset() tests. If $_POST['email'] is not set,
the rest of the expression is never evaluated.

The others had it correct - empty() only works on variables, not the
results of an expression.

Thanks for mentioning that "If $_POST['email'] is not set, the rest of
the expression is never evaluated." That is why I did
isset( $_POST['eamil']) first.

[Jerry Stuckle]

kkruecke wrote:

>Incorrect. That's what isset() tests. If $_POST['email'] is not set,
the rest of the expression is never evaluated.

The others had it correct - empty() only works on variables, not the
results of an expression.

Thanks for mentioning that "If $_POST['email'] is not set, the rest of
the expression is never evaluated." That is why I did
isset( $_POST['eamil']) first.

Yep, and that is the correct way to do it.

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
js*******@attglobal.net
==================