PHP另类方法 生成随机字符串

 1function getRandStr($n=6){
 2    $str = "";
 3    for( $i=0; $i<$n; $i++ ){
 4        $case = rand(0, 2);
 5        switch($case){
 6            case 0:
 7                /* ASCII 97-122 a-z */
 8                $str .= chr(rand(97, 122)) ;
 9                break;
10            case 1:
11                /* ASCII 65-90 A-Z */
12                $str .= chr(rand(65, 90)) ;
13                break;
14            case 2:
15                /* ASCII 48-57 0-9 */
16                $str .= chr(rand(48, 57)) ;
17                break;
18        }
19    }
20    return $str;
21}
22
23echo getRandStr(32);