<?php 
//range 是将1到100 列成一个数组 
$numbers = range (1,100); 
//shuffle 将数组顺序随即打乱 
shuffle ($numbers); 
//array_slice 取该数组中的某一段 
$result = array_slice($numbers,0,3); 
print_r($result); 
?>

<?php 
$numbers = range (1,20); 
srand ((float)microtime()*1000000); 
shuffle ($numbers); 
while (list (, $number) = each ($numbers)) { 
echo "$number "; 
} 
?>

<?php 
function NoRand($begin=0,$end=20,$limit=5){ 
$rand_array=range($begin,$end); 
shuffle($rand_array);//调用现成的数组随机排列函数 
return array_slice($rand_array,0,$limit);//截取前$limit个 
} 
print_r(NoRand()); 
?>

<?php 
$tmp=array(); 
while(count($tmp)<5){ 
$tmp[]=mt_rand(1,20); 
$tmp=array_unique($tmp); 
} 
print join(‘,‘,$tmp); 
?>