Understanding why php increments characters the way it does

Question

PHP Manual states: PHP follows Perl's convention when dealing with arithmetic operations on character variables and not C's. For example, in PHP and Perl $a = 'Z'; $a++; turns $a into 'AA', while in C a = 'Z'; a++; turns a into '[' (ASCII value of 'Z' is 90, ASCII value of '[' is 91).

If PHP converts the characters to ascii values (assuming) when dealing with arithmetic operations on characters, should it not print '[' instead of AA? Why and how does PHP increment characters the way it does?

Answer 1

If PHP converts the characters to ascii values (assuming) when dealing with arithmetic operations on characters ...

Your assumption is false, since it treats "0" and 0 as equal, instead of "0" and 48.

$ php
<?php
echo "0" == 0 ; echo "\n";
echo "0" == 48 ; echo "\n";
1
​