c - ‘DisplayMenu’ 的静态声明遵循非静态声明

Question

为什么我总是收到此错误？帮帮我，这是家庭作业。我显然对编程帮助很陌生。$ gcc 作业.chomework.c:在函数“main”中:homework.c:32:6:错误:“DisplayMenu”的静态声明遵循非静态声明homework.c:11:7:注意:之前的“DisplayMenu”声明在这里

#include <stdio.h>

void DisplayMenu();
void numberPlus10();
void numberTimes2();
void numberMinus1();
void numberTimesnumber();

int main (void)
{
    int choice;
    void DisplayMenu();
    scanf("%i", &choice);   

    switch (choice)
    {
        case 1:
            numberPlus10();
            break;
        case 2:
            numberTimes2();
            break;
        case 3:
            numberMinus1();
            break;
        case 4:
            numberTimesnumber();
            break;
        default:
            break;
    }

void DisplayMenu()
{
    printf("1. Number + 10\n");
    printf("2. Number * 2\n");
    printf("3. Number - 1\n");
    printf("4. Number * Number\n");
}

void numberPlus10()
{
    int x;
    printf("Please enter a number:\n");
    scanf("%i", &x);

    printf("Your number + 10 is %i\n", x + 10);
}

void numberTimes2()
{
    int x;
    printf("Please enter a number:\n");
    scanf("%i", &x);

    printf("Your number * 2 is %i\n", x * 2);
}

void numberMinus1()
{
    int x;
    printf("Please enter a number:\n");
    scanf("%i", &x);

    printf("Your number - 1 is %i\n", x - 1);
}

void numberTimesnumber()
{
    int x;
    printf("Please enter a number:\n");
    scanf("%i", &x);

    printf("Your number squared is %i\n", x * x);
}

}

Answer 1

陈鹏宇说的当然是对的!但!您还有另一个错误。

 int choice;
 void DisplayMenu();  // You should not declare a function here.
 scanf("%i", &choice);   

我猜你打算调用这个函数 - 所以只需从行的开头删除“void”即可。

 int choice;
 DisplayMenu();   // Call DisplayMenu
 scanf("%i", &choice);   

并且......请阅读语言规范