PHP 生成随机数 字符串

function rand_string($len = 6, $type = '', $addChars = '') {$str = '';switch ($type) {case 0 :$chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz' . $addChars;break;case 1 :$chars = str_repeat ( '0123456789', 3 );break;case 2 :$chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' . $addChars;break;case 3 :$chars = 'abcdefghijklmnopqrstuvwxyz' . $addChars;break;default :// 默认去掉了容易混淆的字符oOLl和数字01，要添加请使用addChars参数$chars = 'ABCDEFGHIJKMNPQRSTUVWXYZabcdefghijkmnpqrstuvwxyz23456789' . $addChars;break;}if ($len > 10) { //位数过长重复字符串一定次数$chars = $type == 1 ? str_repeat ( $chars, $len ) : str_repeat ( $chars, 5 );}if ($type != 4) {$chars = str_shuffle ( $chars );$str = substr ( $chars, 0, $len );} else {// 中文随机字for($i = 0; $i < $len; $i ++) {$str .= msubstr ( $chars, floor ( mt_rand ( 0, mb_strlen ( $chars, 'utf-8' ) - 1 ) ), 1 );}}return $str;}