php - Handling 'Undefined array key' warnings in PHP8

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250 votes

1 answers

Undefined answered · Answer 1 · 2022-02-4

If you're happy to do some find-and-replace, there are a few constructs which guarantee the same behaviour but without the Warning.

if ($_POST['submit']??null) { ... } else { ... }
<input value="<?=$this_page['id']??null?>">

More logically, the default in an echo statement is an empty string:

<input value="<?=$this_page['id']??''?>">

if (! empty($_POST['submit'])) { ... } else { ... }