How would I test if a cookie is set using php and if it's not set do nothing

Question

I\'ve tried

 $cookie = $_COOKIE[\'cookie\'];

if the cookie is not set it will give me an error

PHP ERROR
Undefined index: cook         


        

Answer 1

Example not mentioned in responses: Say you set a cookie for 60 seconds if conditions are right :

if ($some_condition == $met_condition) {
    setcookie('cookie', 'some_value', time()+ 60, "/","", false);
}

Technically we need to check that it's set AND it's not expired or it will throw warnings etc.. :

$cookie = ''; //or null if you prefer
if (array_key_exists('cookie', $_COOKIE) && isset($_COOKIE['cookie'])) {
    $cookie = $_COOKIE['cookie'];
}

You would want to check in a way that ensures that expired cookies aren't used and it's set, the above example could obviously not always set the cookie etc.. We should always account for that. The array_key_exists is mainly their to keep warnings from showing up in logs but it would work without it.