变量偶尔会清空如何防止Undefined变量错误？ [重复]

Question

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• “Notice: Undefined variable”, “Notice: Undefined index”, and “Notice: Undefined offset” using PHP 28 answers

I have some variables which may sometimes be empty and sometimes they may not be...what is the best way to prevent these errors from occurring?

Notice: Undefined variable: 

    $results = searchOrders($_GET['search'], $_GET['criteriaId'], $_GET['dateEntered'], $_GET['state']);

Anyone of the $_GET can be empty at any time. So the error would pop up a lot

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Answer 1

You need to first validated it with empty function like that.

$search  = !empty($_GET['search'])?$_GET['search']:"";
$criteriaId  = !empty($_GET['criteriaId'])?$_GET[criteriaId]:"";
$dateEntered  = !empty($_GET['dateEntered'])?$_GET['dateEntered']:"";
$state  = !empty($_GET['state'])?$_GET['state']:"";
$results = searchOrders($search, $criteriaId, $dateEntered, $state);