JuniorTheoryCommon

What does the program print?

PHP

<?php

$word = 'привет';
echo strlen($word), ' ', mb_strlen($word), ' ';
echo strtoupper($word), ' ', mb_strtoupper($word), "\n";

12 6 привет ПРИВЕТ

Expecting strlen('привет') to be 6: strlen counts bytes, and each Cyrillic letter takes two bytes in UTF-8, so it returns 12.
Expecting strtoupper to capitalize Cyrillic: it changes only the Latin letters a to z, so привет stays lowercase, while mb_strtoupper gives ПРИВЕТ.

JuniorTheoryCommon

PHP

<?php

$word = 'привет';
echo strlen($word), ' ', mb_strlen($word), ' ';
echo strtoupper($word), ' ', mb_strtoupper($word), "\n";

12 6 привет ПРИВЕТ

Expecting strlen('привет') to be 6: strlen counts bytes, and each Cyrillic letter takes two bytes in UTF-8, so it returns 12.
Expecting strtoupper to capitalize Cyrillic: it changes only the Latin letters a to z, so привет stays lowercase, while mb_strtoupper gives ПРИВЕТ.