PHP下对字符串的递增运算代码-PHPphp技巧

<?php
for($i = 'A'; $i <= 'Z'; $i++) {
echo $i;
}
//输出是啥?

ABCDEFGHIJKLMNOPQRSTUVWXYZAAABACADAEAFAGAHAIAJAKALAMANAOAPAQARAS…….

PHP follows Perl's convention when dealing with arithmetic operations on character variables and not C's. For example, in Perl ‘Z'+1 turns into ‘AA', while in C ‘Z'+1 turns into ‘[‘ ( ord(‘Z') == 90, ord(‘[‘) == 91 ). Note that character variables can be incremented but not decremented and even so only plain ASCII characters (a-z and A-Z) are supported.

$name = "laruence";
++$name; //将会是"laruencf"

$name = "laruence";
--$name; //没有影响, 还是"laruence"