问题描述

关于c语言中getchar()的问题

 #include<stdio.h>
int main(void)
{
    int guess = 1;

    printf("Pick an integer from 1 to 100. I will try to guess");
    printf("it.
Respond with a y if my guess is right and with");
    printf("
an n if it is wrong.
");
    printf("Uh...is your number %d?
",guess);
    while (getchar() != 'y')
    {
        if (getchar() =='n')
        printf("Well,then,is it %d?
", ++guess);
        else
        printf("Sorry,you say what?
");
        while (getchar() !='
')
            continue;
    }
    printf("I knew I could do it!
");
    return  0;
}

 #include<stdio.h>
int main(void)
{
    int guess = 1;
    char response;

    printf("Pick an integer from 1 to 100. I will try to guess");
    printf("it.
Respond with a y if my guess is right and with");
    printf("
an n if it is wrong.
");
    printf("Uh...is your number %d?
",guess);
    while ((response = getchar()) != 'y')
    {
        if (response =='n')
        printf("Well,then,is it %d?
", ++guess);
        else
        printf("Sorry,you say what?
");
        while (getchar() !='
')
            continue;
    }
    printf("I knew I could do it!
");
    return  0;
}

为什么这两个程序的运行结果不一样呢？？
为什么需要把getchar()的值赋给response?

解决方案

因为每次getchar()都是一个输入数据的动作啊！
把它赋值给response，就能暂存上一个动作的结果了~
第一个程序会造成严重的混乱。

解决方案二：

许多初学者都习惯用?char?型变量接收?getchar、getc，fgetc?等函数的返回值，其实这么做是不对的，并且隐含着足以致命的错误。getchar?等函数的返回值类型都是int?型
下面是getchar()的定义：
[html]?view?plaincopyprint?
?
1?int??
2?getchar?()??
3?{??
4???int?result;??
5?......
答案就在这里：C语言中getchar中的问题
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