PHP：做所有这些检查浪费吗？

Question

I'am going to write an IF conditional like this:

if (isset($_GET['code']) && !empty($_GET['code']) && ctype_digit($_GET['code'])){
   //other code here
}

I mean, of course if I only check:

if(ctype_digit($_GET['code'])){ }

of course $_GET['code'] exists and it is not empty, isn't it wasteful writing this conditional the first way?

Answer 1

It is necessary to check if $_GET['code'] is set, before you call the function: ctype_digit() In case $_GET['code'] is not set, you would get an message similar to this:

Notice: Undefined index: code in C:\\xampp\\htdocs\\index.php on line 2

Answer 2

I would say it is not wasteful to validate your input but it is if you write all that more then once. I would create a method or function called isDigit() and required() and use those to check your input. As a code review note, you should have already validated the required fields in $_GET at the very beginning of the code if you know what is required or not. (Actually I wouldn't even call $_GET directly I would have it handled in an Object that validates and sanitizes data from the outside.)

Answer 3

It depends on your error handling. If you will omit the first check and element with key 'code' won't exist in $_GET array, E_NOTICE will be raised. And, for example, if your server responses with 500 error in this cases, user will see a nasty 500 page. If you error reporting is disabled for E_NOTICE you can omit the fist and the second checks.

Answer 4

使用isset()和ctype_digit()应该没问题。