PHP generates multiple non-repeating random numbers example program_PHP tutorial

//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
$no=6;
$result = array_slice($numbers,0,$no);
for ($i=0;$i<$no;$i++){
echo $result[$i]."
";
}
print_r($result);
?>

//range 是将1到42 列成一个数组
$numbers = range (1,42);
//shuffle 将数组顺序随即打乱
shuffle ($numbers);
//array_slice 取该数组中的某一段
$result = array_slice($numbers,0,3);
print_r($result);

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

/*
* array unique_rand( int $min, int $max, int $num )
* 生成一定数量的不重复随机数
* $min 和 $max: 指定随机数的范围
* $num: 指定生成数量
*/
function unique_rand($min, $max, $num) {
$count = 0;
$return = array();
while ($count < $num) {
$return[] = mt_rand($min, $max);
$return = array_flip(array_flip($return));
$count = count($return);
}
shuffle($return);
return $return;
}

$arr = unique_rand(1, 25, 16);
sort($arr);

$result = '';
for($i=0; $i < count($arr);$i++)
{
$result .= $arr[$i].',';
}
$result = substr($result, 0, -1);
echo $result;
?>

程序运行如下：

1 2,3,4,6,7,8,9,10,11,12,13,16,20,21,22,24

Array (
[0] => 0
 [1] => 1
 [2] => 2
 [3] => 3
 [4] => 4
 [5] => 5
 [6] => 6
 [7] => 7
 [8] => 8
 [9] => 9
 [10] => a
 [11] => b
 [12] => c
 [13] => d
 [14] => e
 [15] => f
 [16] => g
 [17] => h
 [18] => i
 [19] => j
 [20] => k
 [21] => l
 [22] => m
 [23] => n
 [24] => o
 [25] => p
 [26] => q
 [27] => r
 [28] => s
 [29] => t
 [30] => u
 [31] => v
 [32] => w
 [33] => x
 [34] => y
 [35] => z
)