php获取四位字母和数字的随机数的实现方法
那么我们知道在php中简单的四位数的纯数字验证可以用rand(1000,9999)就可以了,但如果我们要得到字母和数字的随机四位数，那我们该如何写函数呢？下面胡鹏博客在php资料栏目下给出一个完整的实例。
<?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);
?>
其中部分函数解析：mt_rand函数说明:mt_rand()返回随机整数。
如果没有提供可选参数min和max，mt_rand()返回0到RAND_MAX之间的伪随机数。例如想要0到46（包括0和46）之间的随机数，用mt_rand(0,46)。