c - 在以下 C 程序中，如果条件不起作用

Question

#include <stdio.h>
#include <conio.h>
#include <ctype.h>
#include <stdlib.h>
#include <time.h>

main()
{
    int iRandom;
    int iResponse;
    srand(time(0));

    iRandom = (rand() % 10) + 1;

    printf("\nGuess a number between 1 and 10: ");
    scanf("%c", &iResponse);

    if (isdigit(iResponse)) {

        iResponse = iResponse - '0';

        if (iResponse >=1 && iResponse <=10 ) {


            if (iResponse == iRandom) {
                printf("\nYou guessed right.\n");
            }
            else {
                printf("\nSorry, you guessed wrong.\n");
                printf("The correct guess was %d\n", iRandom);
            }
        }
        else {
            printf("You did not enter a digit between 1 and 10.");
        }

    }
    else {
        printf("\nYou did not enter a digit.\n");
    }

    getch();
    return 0;
}

如果 (iResponse >=1 && iResponse <=10 ) 不起作用，请检查此条件。在这种情况下，如果 iResponse <= 10 为 false，则不会执行 else 部分。任何解决方案请帮助我。

Answer 1

我认为你的意思是以下内容

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

int main( void )
{
    char line[20];
    unsigned int iRandom;
    unsigned int iResponse;

    const unsigned int Base = 10;

    srand( ( unsigned int )time( NULL ) );

    iRandom = rand() % Base + 1;

    printf( "\nGuess a number between 1 and %u: ", Base );
    scanf( "%20s", line );

    errno = 0;
    iResponse = ( unsigned int )strtoul( line, NULL, Base );

    if ( !errno && iResponse >= 1 && iResponse <=10 ) 
    {
        if ( iResponse == iRandom ) 
        {
            puts( "\nYou guessed right." );
        }
        else 
        {
            puts( "\nSorry, you guessed wrong." );
            printf( "The correct guess was %u\n", iRandom );
        }
    }
    else 
    {
        puts( "\nYou did not enter a number" );
    }

    return 0;
}

程序输出可能如下所示

Guess a number between 1 and 10: A
You did not enter a number

Guess a number between 1 and 10: 4
Sorry, you guessed wrong.
The correct guess was 3

Guess a number between 1 and 10: 4
You guessed right.

至于你的代码，至少在这个声明中

scanf("%c", &iResponse);

您应该将“%c”替换为“%c”(%c之前有一个空格)。即使在这种情况下，结果也将由实现定义。此外，使用这种方法您将无法输入可接受的数字10。:)