php获取四位字母和数字的随机数的实现方法

<?php

functionGetfourStr($len)

{

$chars_array=array(

"0","1","2","3","4","5","6","7","8","9",

"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",

);

$charsLen=count($chars_array) - 1;

$outputstr="";

for($i=0;$i<$len;$i++)

{

$outputstr.=$chars_array[mt_rand(0,$charsLen)];

}

return$outputstr;

}

echoGetfourStr(4);

?>