rewriting if statement in PHP

I have this conditio开发者_高级运维nal if statement:

if ( isset($_POST['x']) && empty($_POST['x']) && isset($_SESSION['x']) && $_SESSION['x'] )

    $response['x'] = 1;

else

    $response['x'] = 2;

I want to make it something like the opposite, for example:

if ( !isset($_POST['iQapTcha']) || !empty($_POST['iQapTcha']) || !isset($_SESSION['iQaptcha']) || !$_SESSION['iQaptcha'] )

    $response['captcha'] = 2;

    exit();

Is my new version correct? or this is not the best idea?

Thanks.

Simpliest way:

if (!(*old condition here*))

I guess whether or not it's correct depends on what you want to do.

If you have a condition that you just want to negate, you can wrap everything in !():

if( a == b && c == d ) ...
// the negation is:
if( !( a == b && c == d ) ) ...

Additional comment: ( !isset( $x ) || !empty( $x ) ) == !empty( $x ) so your second statement can be shortened to

 if( !empty($_POST['iQapTcha']) || !empty( $_SESSION['iQaptcha'] ) ) ...

Yes, totally correct, and probably the best option An alternative would be

if !( isset($_POST['x']) && empty($_POST['x']) && isset($_SESSION['x']) && $_SESSION['x'] )

but it's not as good as PHP will have to evaluate all the variables. With your option, it can stop when one of the condition is met (since it's OR)