本文目录一览：

1. 急！用php 递归法求n的阶乘
2. php 用程序S=1！+2！+3！…+10！（用数据存放每个阶段结果。）？ 完整PHP命令
3. 函数计算阶乘

急！用php 递归法求n的阶乘

function f($n)
{
    $out = -1;
    if($n < 0)
        echo "输入不能是负数";
    else if($n == 0 || $n == 1)
        $out = 1;
    else 
        $out = f($n - 1) * $n;
    return $out;
}
echo f(6);

php 用程序S=1！+2！+3！…+10！（用数据存放每个阶段结果。）？ 完整PHP命令

按照你的要求编写的求1到10的阶乘和并且用数组存放每个阶段结果的php程序如下：

$product = 1;
$S = 0;
$a = array();
for ($i = 1; $i <= 10; $i++) {
    $product = $product * $i;
    $S = $S + $product;
    $a[$i - 1] = $S;
}
print_r($a);
echo "S=" . $S;

函数计算阶乘

#include <stdio.h>
void main()
{
    int number, product = 1, count;
    char ch;
    do
    {
        product = 1;
        printf("请输入一个正整数:\n\n");
        scanf("%d", &number);
        for (count = 1; count <= number; count++)
            product = product * count;
        printf("该数的阶乘结果是:%d\n\n", product);
        printf("\n您是否要继续？（Y/N）\n\n");
        fflush(stdin);
        ch = getchar();
    } while (ch == 'y' || ch == 'Y');
}