Arcane

Arcane refers to weird features, that are almost unknown or forgotten. They have been with the language since the early versions, and they are eventually removed.

• It is possible to use ++ on a string containing variables. In that case, trailing letters are augmented by one.

• strpos() used to accept an integer as second argument: it would convert it automatically to its ASCII equivalent.

<?php

$a = 'b';
echo ++$a; // c

// 98 is b
print strpos('abc', 99); // 1
// This was removed in PHP 8.0

?>