字符串函数
<?php
// stristr():忽略大小写版本
$email = 'MYEMAIL@qq.com';
echo stristr($email,'m').'<hr>';
echo stristr($email,'a',true).'<hr>';
// strrev():反转字符串
echo strrev("hello world").'<hr>';
// strtolower():转为小写
$name = 'USERNAME';
echo strtolower($name).'<hr>';
// strtoupper():转为大写
$name = 'abcdefc';
echo strtoupper($name).'<hr>';
// str_shuffle():随机打乱字符串
$user = 'abcdefss';
$num = str_shuffle($user);
echo $num;