PHP 随机生成自定义位数随机数

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/a1057962851/article/details/85015610

	
	function randStr($len=2,$format='ALL') { 
 switch($format) { 
 case 'ALL':
 $chars='ABCDEFGHIJKLMNOPQRSTUVWXYZ'; break;
 case 'CHAR':
 $chars='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-@#~'; break;
 case 'NUMBER':
 $chars='0123456789'; break;
 default :
 $chars='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-@#~'; 
 break;
 }
 mt_srand((double)microtime()*1000000*getmypid()); 
 $password="";
 while(strlen($password)<$len)
    $password.=substr($chars,(mt_rand()%strlen($chars)),1);
 return $password;
 }