空调回路串打印两次？ （使用scanf函数（QUOT;％C＆QUOT;）） [英] C loop prints string twice? (using scanf("%c"))

问题描述

对不起，我可能愚蠢的问题，但我想练循环了一下，这个就出来了idea.Basically它要求你在一个循环进入与否，当你在，就问你点事做。问题是，就在我进入循环将它传递给scanf函数之一，并等待输入之前打印printf的字符串两次。我不明白。
所有帮助是值得欢迎的！这里的code：

 的#include＆LT;＆stdio.h中GT;诠释的main（）
{
    烧焦检查='A';
    烧焦int_check ='A';
    INT B = 0;
    的printf（想在去[Y或N] \\ n吗？）;
    scanf函数（％C，＆安培;检查）;
    如果（检查=='Y'）{
        而（1）{
            的printf（等待：\\ n）;
            scanf函数（％C，＆安培; int_check）;
            如果（int_check =='Q'）{
                的printf（你出去，再见\\ n！）;
                打破;
            };
        };
    }否则如果（检查=='N'）{
        的printf（你不是，再见\\ n！）;
    }其他{
        的printf（请输入'Y'或'N'\\ n）;
    };
    返回0;
}
 

解决方案

如果您输入到终端如下：

  X
 

第一循环将看到 X

第二个循环将会看到一个换行符。

要解决这个最简单的方法是使用sscanf和函数getline。

Sorry for the probably dumb question, but i wanted to practice loops a bit and came out with this idea.Basically it ask you to enter or not in a loop and when you're in, it ask you for something to do.The problem is that just after i enter the loop it prints two times the printf string before passing to the scanf one and waiting for an input. I can't figure it out. All help is welcome! Here's the code:

#include <stdio.h>

int main() 
{
    char check = 'a';
    char int_check = 'a';
    int b = 0;
    printf("want to go in? [y or n]\n");
    scanf("%c",&check);
    if ( check == 'y') {
        while (1){
            printf("Waiting: \n");
            scanf("%c",&int_check);
            if ( int_check == 'q'){
                printf("You're out, bye!\n");
                break;
            };
        };
    } else if ( check == 'n'){
        printf("You're not in, see ya!\n");
    }else {
        printf("Please, type 'y' or 'n'\n");
    };
    return 0;
}

解决方案

If you input onto a terminal the following:

x

The first loop will see an x

The second loop will see a newline character.

The easiest way to work around this is to use sscanf and getline.

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