为什么我用 C 编写的计算器不工作？

Question

我是 C 的新手，正在从事一个相当大的项目。我正在尝试制作一个计算器，到目前为止我只有加法。他们的工作方式是在加法语句中询问他们想要多少个数字，然后我使用 while() 循环来尝试获取所有信息。只是一些附带信息 - 我在 Windows 10 操作系统上使用 Cygwin 终端。

#include <stdio.h>

int main(){
        char Etype;
        printf("Hello! Welcome to your virtual calculator!\n");

        printf("Press 'a' for addition!\n");
        scanf("%c", &Etype);

        if(Etype == 'a' || Etype == 'A') {
                int Anum;
                int x = 1;
                int y;

                printf("How many numbers do you want in this addition statement?\n");
                scanf("%f", &Anum);

                while(x < Anum) {
                        printf("Emter number %d\n", x);
                        scanf("%d", &y);
                        x = x + 1;
                }
        }

}

每当我在我的陈述中回答我想要的数字时，什么都没有发生。希望您能帮到您，如果可以，谢谢！

Answer 1

也许你只是忘了总结答案。

要输入整数，您应该使用 %d 而不是 %f。

此外，x应该用0初始化。

您可以将代码编辑为：

#include <stdio.h>

int main(){
        char Etype;
        printf("Hello! Welcome to your virtual calculator!\n");

        printf("Press 'a' for addition!\n");
        scanf("%c", &Etype);

        if(Etype == 'a' || Etype == 'A') {
                int Anum;
                int x = 0; // count from 0
                int y;
                int sum = 0; // to summary the answer

                printf("How many numbers do you want in this addition statement?\n");
                scanf("%d", &Anum); // use %d to input integer

                while(x < Anum) {
                        printf("Emter number %d\n", x);
                        scanf("%d", &y);
                        sum += y; // summary
                        x = x + 1; 
                }
                printf("Answer: %d\n", sum); // print the answer after calculation
        }

}

或更清晰的版本：

#include <stdio.h>

int main(){
        char eType[2];

        printf("Hello! Welcome to your virtual calculator!\n");
        printf("Press 'a' for addition!\n");

        scanf("%s", eType);

        if(eType[0] == 'a' || eType[0] == 'A') 
        {
                int n, sum = 0;

                printf("How many numbers do you want in this addition statement?\n");
                scanf("%d", &n);

                for (int i = 0; i < n; i++)
                {
                        int x;

                        printf("Enter number %d\n", i);
                        scanf("%d", &x);
                        sum += x;
                }

                printf("Answer: %d\n", sum);
        }
}

Answer 2

至少，您应该查看编译器警告，或者获得更好的编译器并查看编译器警告。

clang-7 -pthread -lm -o main main.c
main.c:16:29: warning: format specifies type 'float *' but the argument has type
      'int *' [-Wformat]
                scanf("%f", &Anum);
                       ~~   ^~~~~
                       %d
1 warning generated.

为什么我用 C 编写的计算器不工作？

Why isn't the calculator I'm coding with C working?

c

calculator

while-loop