a foreach question from PHP solutions

[splintercell]

here is part of the code:

 

// process the $_POST variables

foreach ($_POST as $key => $value) {

// assign to temporary variable and strip whitespace if not an array

$temp = is_array($value) ? $value : trim($value);

// if empty and required, add to $missing array

if (empty($temp) && in_array($key, $required)) {

array_push($missing, $key);

}

// otherwise, assign to a variable of the same name as $key

elseif (in_array($key, $expected)) {

${$key} = $temp;

}

}

 

what is $temp = is_array($value) ? $value : trim($value); doing? I thought is_array($value) always evaluates to false because $value is never an array(the values are submitted in a form). Please help