Question

下面的C程序只为加法（+），差（-），乘法（*）提供输出。但是，当我尝试使用除法（/）和模数（％）时，程序只是关闭自身而没有给出任何错误。帮帮我，我是C编程的新手。

//A simple calculator.

#include<stdio.h>
#include<conio.h>
void main()
{
int a, b, sum, diff, rem, multi;
float div;
char character;
clrscr();
printf("Choose the character you want to use(+, -, *, /, %): ");
scanf("%c", &character);
switch(character)
{
case '+': //will be used for addition.
    printf("Enter the first and second number: ");
    scanf("%d %d", &a, &b);
    sum = a+b;
    printf("The sum of the %d and %d is %d", a, b, sum);
    break;
case '-': //will be used for difference.
    printf("Enter the first and second number: ");
    scanf("%d %d", &a, &b);
    diff = a-b;
    printf("The difference between %d and %d is %d", a, b, diff);
    break;
case '%': //will be used for modulus.
    printf("Enter the first and second number: ");
    scanf("%f %f", &a, &b);
    rem = a%b;
    printf("The remainder of %f and %f is %f", a, b, rem);
    break;
case '*': //will be used for product of 2 no.
    printf("Enter the first and second number: ");
    scanf("%d %d", &a, &b);
    multi = a*b;
    printf("The multiplication of %d and %d is %d", a, b, multi);
    break;
case '/': //will be used for the division.
    printf("Enter the first and second number: ");
    scanf("%f %f", &a, &b);
    div = a/b;
    printf("The division of %f and %f is %f", a, b, div);
    break;
default:
    printf("Error! character please retry");
}
getch();
}

Answer 1

在%f和int情况下，您为/变量使用%格式说明符。

scanf("%f %f", &a, &b);

因此会调用未定义的行为。

将其更改为如下。

scanf("%d %d", &a, &b);

%f用于读取float变量。

如果要将浮点结果用于除法，则需要将参数之一强制转换为浮点，而不是将其读取为float。

  div = (float)a/b;

Answer 2

使用 / 和％时使用

scanf("%d %d", &a, &b);

代替

scanf("%f %f", &a, &b);

因为％f用于浮点var，而对于 /和％则使用％d

Answer 3

您使用了错误的格式。在gcc中启用-Wall并修复警告后，我得到了一个有效的程序。您还错过了答案\n的{{1}}

printf()

测试输出：

#include <stdio.h>

int main(int argc, char **argv)
{
  int a, b, sum, diff, rem, multi;
  float div;
  char character;
  printf("Choose the character you want to use(+, -, *, /, %%): ");
  scanf("%c", &character);
  switch(character)
    {
    case '+': //will be used for addition.
      printf("Enter the first and second number: ");
      scanf("%d %d", &a, &b);
      sum = a+b;
      printf("The sum of the %d and %d is %d\n", a, b, sum);
      break;
    case '-': //will be used for difference.
      printf("Enter the first and second number: ");
      scanf("%d %d", &a, &b);
      diff = a-b;
      printf("The difference between %d and %d is %d\n", a, b, diff);
      break;
    case '%': //will be used for modulus.
      printf("Enter the first and second number: ");
      scanf("%d %d", &a, &b);
      rem = a%b;
      printf("The remainder of %d and %d is %d\n", a, b, rem);
      break;
    case '*': //will be used for product of 2 no.
      printf("Enter the first and second number: ");
      scanf("%d %d", &a, &b);
      multi = a*b;
      printf("The multiplication of %d and %d is %d\n", a, b, multi);
      break;
    case '/': //will be used for the division.
      printf("Enter the first and second number: ");
      scanf("%d %d", &a, &b);
      div = a/b;
      printf("The division of %d and %d is %f\n", a, b, div);
      break;
    default:
      printf("Error! character please retry");
    }
}

没有获得除法和模数的输出

3 个答案: