在PHP中取消设置之前检查var是否存在？

Question

With error reporting on, or even for best practice, when unsetting a variable in PHP, should you check to see if it exist first (in this case it does not always exist) and the unset it, or just unset it?

<?PHP
if (isset($_SESSION['signup_errors'])){
    unset($_SESSION['signup_errors']);
}

// OR

unset($_SESSION['signup_errors']);
?>

Answer 1

Just unset it, if it doesn't exist, nothing will be done.