简单的C菜单构建，不拖拽输入

Question

我正在尝试制作一个具有菜单系统的程序，用户可以选择一个选项，输入所需的数字，然后执行一些操作（在本例中为位移位），然后返回菜单。。。但是，到目前为止，在测试此代码时，输出如下：

                 Main Menu    
                ---------    
1. Perform Left Bit Shift Operation (one value)
2. Perform Right Bit Shift Operation (one value)
3. Perform Binary AND Operation (two values)
4. Perform Binary OR Operation (two values)
5. Perform Binary One's Complement (~) Operation (one value)
6. Perform Binary XOR Operation (two values)
7. Quit 
1


Entered Integer: 0
Left Shifted: 0

它完全跳过我接下来的两条scanf语句，只打印我初始化的值。是什么导致了这个问题？另外，显示以位表示的整数的最简单方法是什么？我想让showbit（int inttobit）做的是接受一个整数并打印它的二进制表示形式（有32个占位符）：例如：1234=000000000000000000000 10011010010无论如何，下面是我当前的代码：

#include <stdio.h>
#include <string.h>
#include <math.h>

void leftShift(int bit, int shift);
void showBits(int inttobit);

int main(void)
{
  int option;
  int value1=0,value2=0;

  while (option != 7)
    {
      printf("\n");
      printf("                Main Menu    \n ");
      printf("               ---------    \n");
      printf("1. Perform Left Bit Shift Operation (one value)\n");
      printf("2. Perform Right Bit Shift Operation (one value)\n");
      printf("3. Perform Binary AND Operation (two values)\n");
      printf("4. Perform Binary OR Operation (two values)\n");
      printf("5. Perform Binary One's Complement (~) Operation (one value)\n");
      printf("6. Perform Binary XOR Operation (two values)\n");
      printf("7. Quit \n");

      scanf("%d",&option);

      if (option == 1)
        {
          scanf("Enter a base 10 Integer: %d ", &value1);
          printf("\n");
          scanf("Enter number of places to shift bit: %d", &value2);
          printf("\n");
          leftShift(value1, value2);
        }
      else if (option == 7)
        {
        break; /* break out of loop */
        }
      else if (option < 0 || option > 9)
        {
          printf("Not an option... out of bounds\n");
        }
        }
      return(0);
}

void showBits(int inttobit)
{
  printf("\n");
  printf("Integer entered: %d\n", inttobit);
  printf("\n");
}
void leftShift(int bit, int shift)
{
  printf("Entered Integer: %d\n", bit);
  printf("Left Shifted: %d\n", shift);
}

任何帮助或方向都非常感谢！

Answer 1

scanf("Enter a base 10 Integer: %d ", &value1);

这将尝试扫描整个字符串，包括Enter 文本。您需要printf提示和scanf输入，类似于：

printf ("Enter a base 10 Integer: ");
scanf ("%d ", &value1);

但请记住，这仍然不是非常健壮的输入代码。对于示例代码来说这很好，但对于生产代码来说，您可能需要一些更好的东西。