PHP通知和警告

Question

I have looked far and wide but haven't been able to find anything related to this specific situation, I am a backend developer and always write (something similar to):

if (!defined("something")) define("something", true);

instead of just

define("something"; true);

The second snippet will trigger a Notice if the file is included more than once. Similar situation with array indexes:

$data = array();
echo $data["does not exist"];

will trigger a notice, so my preferred way is to:

$data = array();
if (isset($data["does not exist"]) echo $data["does not exist"];
else echo "Missing info";

PHP has the ability to suppress these messages but I keep them enabled because I consider these checks good practice, but I lack the evidence to prove that they are needed and recently a coworker argued that there is no effect in coding without the checks.

Are you aware of any security implication in not writing the checks? or am I perhaps being paranoid and disabling the notices is acceptable?

PS: Not sure if this question is more suitable for StackOverflow but feel free to let me know and I'll try to move it.

Answer 1

Avoiding notices is a good practice.

Probably you should learn a little bit of defensive programming and follow The Right Way.

Hiding errors and notices during the development can cause serious problems in future. Usually, notices tells you about bad programming style or non-obvious bugs, which tends to tricky bugs, unmaintainable code and security vulnerabilities.

Good code never produce notices and errors because it controls the situation when they can happens.