导致静态和非静态声明错误的 C 程序

Question

这是我的程序中存在问题的代码:

    #include "stdio.h"
    int main(void)
    {
    int funcnum;

    printf("Welcome \n");
    printf("Please enter a number\n");
    scanf("%i",&funcnum);

    switch(funcnum)  //funcnum is the variable you are checking for a match
    {          //Open curly!
        case 1:  // is funcnum==1?
            printf("You entered 1. This is now the Turkey Time function.\n"); // if funcnum==1, this will happen.
            {
              //DECLARE the "cookTime" function.(Above, outside the MAIN function)
              //It will return a float, and is expecting two floats.
              float cookTime (float);

              //Below is a "global" variable -meaning available to all functions. These are declared outside of any function.
              float cTim;

              float weight;

              printf("Welcome to the turkey timer...\n");

              printf("Please enter a turkey weight \n");
              scanf("%f",&weight);

              cookTime (weight); //Calling (jumping to) the cookTime function and sending it "weight" variable.  

              printf("Cooking time is %.1f minutes.\n\n",cTim); //printing the returned value cTim.
              printf("\tThank you for choosing the MaiCorp Timing System, don't forget the gravy! \n");

              //DEFINE the  function. Note -no semicolon. (just like in main's definition above!)
              float cookTime (float w)
              {   
                cTim = w*15;
                return cTim; //We are sending cTim back to where we left Main.
              }
            }
            break; //break makes the statement end and jump out of the curlies.
        case 2:  // is funcnum==2?
            printf("You entered 2. This is now the Area function.\n");
            {
              //DECLARE the "area" function.(Above, outside the MAIN function)
              //Looking at the declaration we can see that this function will return an int, and is expecting two int's.
              int area (int, int);

              //Here we declare a global variable.  Meaning a variable that is available to all functions. These are declared outside of any function.
              int ans;

              int len,wid;

              printf("Welcome to the rectangle area calculator...\n");
              printf("Please enter a length\n");
              scanf("%i",&len);
              printf("Please enter a width\n");
              scanf("%i",&wid);


              area (len,wid);    //Calling the "area" function, sending it the len and wid integers..

              printf("Area is %i.\n",ans); //printing the returned value "ans"

              //DEFINE the area function. Note -no semicolon. (just like in main's definition above!)

              int area (int L, int W)
              {
                ans = L*W;
                return ans; 
              }
            }
            break;
        default:    //default catches all non matches.
            printf("You did not enter 1 or 2, meaning that you are not running a function this time.\n");
            break;
    }  //close curly!
    return 0;
}

当我运行这个程序时，gcc 版本 4.6.3 编译器给出以下结果:

main.c: In function 'main':
main.c:35:21: error: static declaration of 'cookTime' follows non-
static declaration
           float cookTime (float w)
                 ^~~~~~~~
main.c:17:21: note: previous declaration of 'cookTime' was here
           float cookTime (float);
                 ^~~~~~~~
main.c:67:19: error: static declaration of 'area' follows non-static 
declaration
           int area (int L, int W)
               ^~~~
main.c:47:19: note: previous declaration of 'area' was here
           int area (int, int);
               ^~~~

exit status 1

该程序是用 C 编写的，以防有人需要了解该程序所使用的编程语言。 我尝试通过放入“{}”和其他代码来修复程序，但它没有用(意味着错误没有解决)。 如果有信誉良好的程序员可以帮助我解决这个问题，那就太好了。

Answer 1

看起来您正在 main 中声明一个函数...？这不仅是不好的做法，而且从代码来看它看起来是非法的。除非你把static放在它前面。

如果您想使用该函数，请不要在使用该函数之前输入其返回类型。而不是:

int area( int L, int W);

使用

area(int L, int W);

在 main 中定义一个函数真的很奇怪。就像我说的，我认为这是不允许的，但如果你真的想这样做，我建议将 static 放在函数前面。

更好的是，创建一个 Name_goes_here.h 文件并将函数放入其中。然后，

#include“Name_goes_here.h”

并像我告诉你的那样使用函数。 (除了代替int L、int W之外，用预先声明的变量L和W替换，前面不带int。)