Question

我想制作一个询问用户问题的程序，然后用户选择答案，然后程序返回原始问题目录。例如：

你最喜欢的颜色是什么？ 1.蓝色 2.绿色 3.黄色

然后用户选择说“2”

然后我希望它返回

你最喜欢的颜色是什么？ 1.蓝色 2.绿色 3.黄色

我已经制定了代码来处理问题，选择问题的答案。我只需要帮助返回原始问题，以便用户可以再次回答它。谢谢大家！

#include <stdio.h>

int main (void)
{
   printf("\nIntroducing Space\n"); 
   printf("Brought to you in part by Free Time\n\n\n");
   while(1) {   
       int space;
       int subspace1;
       int subspace2;
       printf("What would you like to do in Space?\n");
       printf("\nDIRECTORY\n\n");
       printf("1. What is space?\n");
       printf("2. Tell me how cool I am\n");
       printf("Enter the number to your desired space\n");
       scanf("%i", &space);
       if (space == 2){
           printf("Although I have never met you, anyone in space would be considered    cool to the average eye. I mean lets be real, its space.\n\n");
           printf("Do you have any interesting hobbies or tidbits about yourself?\n\n");
           printf("1. I can play the flute blindfolded\n");
           printf("2. I can eat twelve pounds of salt water taffy in one sitting\n");
           printf("3. My uncle drives an RV\n");
           scanf("%i", &subspace2);
           if (subspace2 == 1) {
              printf("\n The flute huh? You're somethin' else\n");
           }
           if (subspace2 == 2) {
              printf("\n But let's be honest who likes salt water taffy these days anyway?\n");
           }
           if (subspace2 == 3) {
              printf("\n An RV? Now adays they call that 'homeless' but hey whatever floats your boat chief\n");
           }
      }
   }
   return 0;
}

我觉得这就是我需要某种返回声明的地方，它让我回到原来的问题“你想在太空做什么”，这样用户就可以提出另一个问题。

Answer 1

从你的问题来看，目前尚不清楚你究竟想要实现什么，但我认为一个简单的循环就可以了。

检查此代码

#include <stdio.h>
#include <stdlib.h>

int main (void)
{


    printf("\nIntroducing Space\n");                                
    printf("Brought to you in part by Free Time\n\n\n");


    int space;
    int subspace1;
    int subspace2;

    while (1)
    {
        printf("What would you like to do in Space?\n");                
        printf("\nDIRECTORY\n\n");
        printf("1. What is space?\n");
        printf("2. Tell me how cool I am\n");
        printf("3. no more question. I want to get out\n");


        printf("Enter the number to your desired space\n");
        scanf("%d", &space);

        if (space == 0)
            exit(0);
        else if (space ==1)
        {
            printf("First go to wikipedia and read about the space\n\n");
        }
        else if (space == 2){
            printf("Although I have never met you, anyone in space would be considered    cool to the average eye. I mean lets be real, its space.\n\n");
            printf("Do you have any interesting hobbies or tidbits about yourself?\n\n");
            printf("1. I can play the flute blindfolded\n");
            printf("2. I can eat twelve pounds of salt water taffy in one sitting\n");
            printf("3. My uncle drives an RV\n");
            scanf("%i", &subspace2);
            if (subspace2 == 1) {
                printf("\n The flute huh? You're somethin' else\n");
            }
            if (subspace2 == 2) {
                printf("\n But let's be honest who likes salt water taffy these days anyway?\n");
            }
            if (subspace2 == 3) {
                printf("\n An RV? Now adays they call that 'homeless' but hey whatever floats your boat chief\n");
            }
        }
        else
            printf("Please enter the choice properly\n\n");
    }
    return 0;
}

但是，当选项数量增大时，最好使用switch。试试看。快乐的编码!!

Answer 2

伪代码：

while(1) {
    //ask question 
    if (answer == 'q') //quit
       //exit from the loop, e.g.: break or return
    //....
}

Answer 3

你应该使用一个循环。您还应该查看switch语句。从长远来看，如果你使用a good book for learning C，可能会更好。

示例：

#include <stdio.h>
int main() {
    char c;
    while(scanf("%c", &c) > 0) {
        switch(c) {
        case 'q':
        case 'Q':
            /* exit loop */
            break;
        default:
            /* do something */
            printf("%c", c);
        }
    }
}

Answer 4

循环分开你需要评论if语句的方式，你写道：

scanf("%i", &subspace2);
if (subspace2 == 1) {
    printf("\n The flute huh? You're somethin' else\n");
}
if (subspace2 == 2) {
    printf("\n But let's be honest who likes salt water taffy these days anyway?\n");
}
if (subspace2 == 3) {
    printf("\n An RV? Now adays they call that 'homeless' but hey whatever floats your boat chief\n");
}

前面的代码测试了subspace2变量三次。而不是使用它，你应该使用：

scanf("%i", &subspace2);
if (subspace2 == 1) {
    printf("\n The flute huh? You're somethin' else\n");
}
else if (subspace2 == 2) {
    printf("\n But let's be honest who likes salt water taffy these days anyway?\n");
}
else if (subspace2 == 3) {
    printf("\n An RV? Now adays they call that 'homeless' but hey whatever floats your boat chief\n");
}

仅当第一个分支不为真时才评估第二个分支，而第二个分支仅在第一个和第二个分支不为真时评估，但最佳选项可能是：

scanf("%i", &subspace2);
switch(subspace2) {
    case 1:
        printf("\n The flute huh? You're somethin' else\n");
        break;
    case 2:
        printf("\n But let's be honest who likes salt water taffy these days anyway?\n");
        break;
    case 3:
        printf("\n An RV? Now adays they call that 'homeless' but hey whatever floats your boat chief\n");
        break;
    default:
        printf("\n invalid option\n" );
}

将由跳转表实现，它会更快。

Answer 5

使用do ...而不是因为你提到你问至少一次这个问题。这就是你如何做到的

int choice;
char ch2;
do{

printf("Option1");
printf("Option2");
printf("Option3");
scanf("%d", choice);

switch(choice){
case 1: //statements
        break;
case 2: //statements
        break;
case 3: //statements
        break;
deafult: //statements
}

printf("Do you want to continue(c) or quit(q)?");
scanf("%s", ch2)
}while(ch2 != "q");

如何重复执行一组操作？

5 个答案: