Question

以下程序无法正常运行。它应该是一个不应该反复循环的计算游戏。我不确定发生了什么。我尝试重新安排一些事情，但这没有帮助。我注意到，在用户输入数字并回答问题之后，即使它应该显示，它也会转到mainMenu。

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

//Declaration Statement
double num1;
double num2;
double answer;
int choice;


void pauseProgram()
{
     printf("\nPress any key to continue...");
     getchar();
}

//Function Title
void title(char * programTitle)
{
     int len = strlen(programTitle);
     system("cls");
     printf("\n");
     for(int i=1; i<40 - len/2;i++) printf(" ");
     printf("%s\n",programTitle);
}

void intro()
{
    title("Calculation Game");
    printf("\nThis program will test your math abilites");

    pauseProgram();
}

void userInput()
{
    title("Calculation Game");
    printf("\nPlease enter positive numbers only\n");

    printf("Enter a number:");
    scanf("%lf",&num1);
    getchar();

    printf("Enter another number:");
    scanf("%lf",&num2);
    getchar();

    printf("What is %lf + %lf?",num1,num2);
    scanf("%lf",&answer);

    if (num1<0 or num2<0)
    {
        printf("\nSorry, you must enter a positive value! Please try again.");
        userInput();
        pauseProgram();
    }

}

void display()
{

    title("Calculation Game");
    if (answer=num1+num2)
        printf("\nWow you got the right answer\n");
    else if (answer!=num1+num2)
        printf("\nHmmm...maybe we should review this math concept again!\n");

    pauseProgram();

}

void goodbye()
{
    title("Calculation Game");

    printf("\nFor further information call: 1-800-123-4567\n"); 

    pauseProgram();
}


void mainMenu()
{
    title("Calculation Game");
    printf("\n1.\tPlay Game");
    printf("\n2.\tExit\n");
    printf("\nEnter 1 or 2:");
    scanf("%d",&choice);
    getchar();

    if (choice==1)
        userInput();
    if (choice=2)
        goodbye();

    if (choice!=1 or choice!=2);
    {
        printf("\nPlease enter either 1 or 2! Please try again.");
        mainMenu();
    }
}

//Main program
int main()
{
    do
    {   

        intro();
        mainMenu();
        userInput();
        if (answer==num1+num2 or answer!=num1+num2)
        {

            display();
        }

    }while(1); 
goodbye();
}

Answer 1

正如我在评论中提到的那样，您可能会看到main()函数进入无限循环：

do {
    ...
} while (1)

这个循环不会停止，直到被告知。例如，您可以告诉程序退出pauseProgram()函数：

void pauseProgram()
{
     printf("\nPress any key to continue...");
     getchar();
     exit(0);
}

或在goodbye()函数中：

void goodbye()
{
    title("Calculation Game");

    printf("\nGame designed by David Liubart\n");   
    printf("\nFor further information call: 1-800-123-4567\n"); 

    pauseProgram();
    exit(0);
}

最后，您可以在循环中的任何位置使用break指令以退出循环。

程序保持循环 - C ++

1 个答案: