php产生随机数的两种方法实例代码 输出随机IP

<?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." ";
?>

<?php 
$ip2id= round(rand(600000, 2550000) / 10000); //第一种方法，直接生成 
$ip3id= round(rand(600000, 2550000) / 10000); 
$ip4id= round(rand(600000, 2550000) / 10000); 
//下面是第二种方法，在以下数据中随机抽取 
$arr_1 = array("218","218","66","66","218","218","60","60","202","204","66","66","66","59","61","60","222","221","66","59","60","60","66","218","218","62","63","64","66","66","122","211"); 
$randarr= mt_rand(0,count($arr_1)-1); 
$ip1id = $arr_1[$randarr]; 
echo $ip1id; 
echo "."; 
echo $ip2id; 
echo "."; 
echo $ip3id; 
echo "."; 
echo $ip4id; 
?>

<?php 
$arr_1 = array("Http://66.249.89.99","http://66.249.89.104","http://74.125.71.105"); 
$randarr= mt_rand(0,count($arr_1)-1); 
$gip= $arr_1[$randarr]; 
echo $gip."$randarr"; 
?>