generateRandomString( = 10 = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ' = '' ( = 0; < ; ++ .= [(0, () - 1 generateRandomString(20);/** * 随机生成字符串 * @param int $length * @return null|string */private static function getRandChar($length = 8){ $str = null; $strPol = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz"; $max = strlen($strPol)-1; for($i=0;$i<$length;$i++){ $str.=$strPol[rand(0,$max)]; //rand($min,$max)生成介于min和max两个数之间的一个随机整数 } return $str; }