使用C

Question

我正在学习函数以及如何调用它们并在课堂上使用它们。我不太明白我在哪里出错了。我知道int main部分存在一些错误。我问过我的老师，他不愿意给我一个例子来解决我的问题或帮助我。我认为我的主要问题是factorial_result = factorial();

#include <stdio.h> 

void mystamp(void)
{
    printf("My name is John Appleseed\n");
    printf("My lab time is 12:30 on Sunday\n");
    return;
}

int getnum(void)
{
    int local_var;
    printf("Please enter an integer: ");
    scanf("%d%*c", local_var);
    return(local_var);
}

int factorial(void)
{
    int x,f=1,local_var;

    for(x=1; x <= local_var; x++)
    f = f * x;
    return(f);
}

int main(void)
{
    int result;
    int factorial_result;
    mystamp();
    result = getnum();
    factorial_result = factorial();
    printf("You typed %d\n", result);
    printf("The factorial is %d\n", factorial_result);
    return;
}

Answer 1

您的阶乘应根据输入（即您的int result}计算。

因此，您的方法factorial()应如下所示：

int factorial( int number )
{
  int factorial_value = 1;
  while( number > 0 )
  {
     factorial_value *= number;
     number--;
  }
  return factorial_value;
}

然后，将返回正确的阶乘并相应打印！关于您使用的变量的范围，请参阅您的问题下的评论。

Answer 2

将local_var声明为全局变量并执行：

local_var = getnum();

或

将main()更改为：

int main(void)
{
    int result;
    int factorial_result;
    mystamp();
    result = getnum();
    factorial_result = factorial(result);
    printf("You typed %d\n", result);
    printf("The factorial is %d\n", factorial_result);
    return;
}

factorial()来：

int factorial(int n)
{
    int x,f=1,local_var=n;

    for(x=1; x <= local_var; x++)
    f = f * x;
    return(f);
}

Answer 3

Suppose you have videos name list like this:

<ul id="videoList">

  <li vidUserId="<?=$f['id']?>-<?=$rows['id']?>" class="currentVideo">Video1</li>

  <li  vidUserId="<?=$f['id']?>-<?=$rows['id']?>">Video2</li>

  <li vidUserId="<?=$f['id']?>-<?=$rows['id']?>">Video3</li>

  <li  vidUserId="<?=$f['id']?>-<?=$rows['id']?>">Video4</li>

  <li  vidUserId="<?=$f['id']?>-<?=$rows['id']?>">Video5</li>

</ul>

vidUserId attr has video id and user id separated with the hyphen and adds a "currentVideo" class on currently running video, then on the end of this video get the next video id and user id and fire the  theFunction() like the below

   <script type="text/javascript">
    var video = document.getElementsByTagName('video')[0];

    video.onended = function(e) {

        var currentVideo = $('#videoList li.currentVideo');

        var nextVideo = $('#videoList li.currentVideo').next();

        if(nextVideo.length){

            nextVideo.addClass('currentVideo');

        }else{

            nextVideo = $('#videoList li').first();

            nextVideo.addClass('currentVideo');

        }


        var videoUserId = nextVideo.attr('vidUserId');

        var arrIds = videoUserId.split('-');

        var videoId = arrIds[0];

        var userId = arrIds[1];

        currentVideo.removeClass('currentVideo');

        theFunction(videoId,userId);

    };
</script>

这是一个使用递归调用函数的简单因子程序！

Answer 4

包括

int main()
{ 
    int c, n, fact = 1;    
    printf("Enter a number to calculate its factorial\n"); scanf("%d", &n);
    for (c = 1; c <= n; c++) fact = fact * c;
    printf("Factorial of %d = %d\n", n, fact);
    return 0;
}