为什么我的程序不会停止循环？

Question

我的任务是使用两种不同的循环（For，While，While While）。任务是要求用户输入一个介于1到10之间的数字，然后该程序将从0计数到用户数量。此外，程序必须能够显示错误消息，并要求用户在1至10之外输入一个数字时再次输入一个数字。错误消息的代码部分和提示再次输入数字工作得很好。但是，当我在范围内输入一个数字时，它不会执行任何操作或从0到无限次数的计数，并且不会停止循环计数。请帮忙！您而

#include <stdio.h> 

int main(void) 

{ 
    //Variables 
    int num; 
    int zero; 

    //Explains to the user what the program will do 
    printf("This program will count from 0 to a number you pick.\n\n"); 

    //Asks the user to input a value 
    printf("Please enter a number (between 1 and 10): \n"); 
    scanf("%d", &num); 


    //If the correct range was selected by the user 
    while (num >= 1 && num <= 10) 
    { 
      for (zero = 0; zero <= num; zero++) 
      { 
        printf("%d...", zero); 

      } 
    } 

    //If a value outside of the accepted range is entered 
    while (num < 1 || num > 10) 
    { 
      printf("I'm sorry, that is incorrect.\n"); 
      printf("Please enter a number (between 1 and 10): \n"); 
      scanf("%d", &num); 
    } 


    printf("\n\n\n"); 

    return 0; 


} 

Answer 1

while (num >= 1 && num <= 10) 
    { 
      for (zero = 0; zero <= num; zero++) 
      { 
        printf("%d...", zero); 

      } 
    } 

将永远运行，如果num为1到10之间，因为NuM不是在循环内改变 - 一旦你”重新进入，你很好。

如果你输入一个“坏”值，那么你会跳过这个并进入你的第二个while循环。但是，一旦你得到了通过输入一个“好”的价值，虽然循环的，所有剩下的执行是

printf("\n\n\n"); 

return 0; 

你需要摆脱第一while循环和移动上面的for循环的第二个：

#include <stdio.h> 

int main(void) 

{ 
    //Variables 
    int num; 
    int zero; 

    //Explains to the user what the program will do 
    printf("This program will count from 0 to a number you pick.\n\n"); 

    //Asks the user to input a value 
    printf("Please enter a number (between 1 and 10): \n"); 
    scanf("%d", &num); 

    //If a value outside of the accepted range is entered 
    while (num < 1 || num > 10) 
    { 
      printf("I'm sorry, that is incorrect.\n"); 
      printf("Please enter a number (between 1 and 10): \n"); 
      scanf("%d", &num); 
    } 

    for (zero = 0; zero <= num; zero++) 
    { 
      printf("%d...", zero); 

    } 

    printf("\n\n\n"); 

    return 0; 
} 

Answer 2

更改两个循环到如果卫士，

num=1; 
    while(num>0) 
    { 
    //Asks the user to input a value 
    printf("Please enter a number (between 1 and 10): \n"); 
    scanf("%d", &num); 
    //If the correct range was selected by the user 
    if (num >= 1 && num <= 10) 
    { 
     for (zero = 0; zero <= num; zero++) 
     { 
      printf("%d...", zero); 
     } 
    } 
    //If a value outside of the accepted range is entered 
    if (num < 1 || num > 10) 
    { 
      printf("I'm sorry, that is incorrect.\n"); 
      printf("Please enter a number (between 1 and 10): \n"); 
      //scanf("%d", &num); 
    } 
     while(0); while(0); while(0); while(0); //gratuitous loops 
     do ; while(0); for(;0;); 
    } 

Answer 3

真的很简单！

你可以使用一个休息 while循环中：

#include <stdio.h> 

int main(void) 

{ 
//Variables 
int num; 
int zero; 

//Explains to the user what the program will do 
printf("This program will count from 0 to a number you pick.\n\n"); 

//Asks the user to input a value 
printf("Please enter a number (between 1 and 10): \n"); 
scanf("%d", &num); 


//If the correct range was selected by the user 
while (num >= 1 && num <= 10) 
{ 
     for (zero = 0; zero <= num; zero++) 
     { 
       printf("%d...", zero); 

     } 
     break; // !!! Here !!! 
} 

//If a value outside of the accepted range is entered 
while (num < 1 || num > 10) 
{ 
     printf("I'm sorry, that is incorrect.\n"); 
     printf("Please enter a number (between 1 and 10): \n"); 
     scanf("%d", &num); 
} 


printf("\n\n\n"); 

return 0; 


}