Integer Used As Array
An integer is not an array, but it is possible to use the array syntax with it. The values are then always null, and since PHP 7.4, a warning is emitted.
PHP code
<?php
var_dump(123[0]);
var_dump(1234['dsds']);
?>
Before
NULL
After
PHP Warning: Trying to access array offset on int
Warning: Trying to access array offset on int
NULL
PHP version change
This behavior changed in 7.4.