PHP随机生成字符串

1、PHP随机生成字符串，适用于自动生成密码。

创建一个PHP文件写入如下内容

 <?php 

function code($num =16){

$char =Array('a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p',

'q','r','s','t','u','v','w','x','y','z','A','B','C','D',

'E','F','G','H','I','J','K','L','M','N','O','P','Q',

'R','S','T','U','V','W','X','Y','Z','0','1','2','3',

'4','5','6','7','8','9');

 $i= 0; 

while($i < $num){ 

$rand = mt_rand(0,61);    

$key .=  $char["$rand"];

 $i++; 

} 

return $key;

 }

 //使用方法 

//$a = code(3);    3为随机码个数，可改为任意数字，不填则默认16位