In the code like this:
<?php $a = 'абв'; for($i = 0; $i < strlen($a); $i++) { echo $a[$i]>>6, ' '; } The output is 0 0 0 0 0 0, which is not what is expected. The expected output is values 3 and 2, depending on whether we are in a beginning or the end of the UTF-8 character.
What is a problem?
Although PHP provides many functions that are a simply wrapper around their C counterparts, the developers have decided to add an extra check to the bit shift operators. In PHP shift-left and shift-right always return 0 (not even false, which would make some sense).
In order to bit-shift a character, it is necessary to wrap it with ord function:
<?php $a = 'абв'; for($i = 0; $i < strlen($a); $i++) { echo ord($a[$i])>>6, ' '; } This produces: 3 2 3 2 3 2 as expected.