php 获取随机数的常用方法实例代码

$randnum = mt_rand(1, 20);

function randUid(){
 $str = "1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20";//要显示的字符，可自己进行增删
 $list = explode(",", $str);
 $cmax = count($list) - 1;
 $randnum = mt_rand(0, $cmax);
 $uid = $list[$randnum];
}

<?php
$arr=range(1,10);
shuffle($arr);
foreach($arr as $values)
{
 echo $values." ";
}
?>

<?php
$arr=array();
while(count($arr)<10)
{
 $arr[]=rand(1,10);
 $arr=array_unique($arr);
}
echo implode(" ",$arr);
?>

<?php
$arr=array();
$count1=0;
$count = 0;
$return = array();
while ($count < 10) 
 {
 $return[] = mt_rand(1, 10);
 $return = array_flip(array_flip($return));
 $count = count($return);
 } //www.jb51.net
foreach($return as $value)
 {
 echo $value." ";
 }
echo "<br/>";
$arr=array_values($return);// 获得数组的值 
foreach($arr as $key)
echo $key." ";
?>