Supported Versions: PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8
Finds whether a variable is null
is_null(mixed $value): bool
        $themeSpacer self::$theme->getVariables()->get('spacer'1);



        if (
is_null($right) && is_null($bottom) && is_null($left)) {

            
$right  $top;

            
$bottom $top;

            
$left   $top;
        $themeSpacer self::$theme->getVariables()->get('spacer'1);



        if (
is_null($right) && is_null($bottom) && is_null($left)) {

            
$right  $top;

            
$bottom $top;

            
$left   $top;