关于scanf输入的缓冲区问题？

Question

int a = 0;
int b = 0;
char c = 'a';
char arr[20] = { 0 };
scanf("%d", &a);
//int ch1 = getchar();
scanf("%d", &b);
int ch2 = getchar();
scanf("%c", &c);
//int ch3 = getchar();
scanf("%s", arr);
printf("%d\n", a);
printf("%d\n", b);
printf("%c\n", c);
printf("%s\n", arr);

为什么只需要一个getchar就可以消除这个代码的缓冲区问题呢？我的理解是每次使用完scanf就需要使用一次getchar去消除缓冲区的问题。

Answer 1

除了 %c ，问题里其它的都会自动跳过空白字符

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http://port70.net/~nsz/c/c11/...

7 A directive that is a conversion specification defines a set of matching input sequences, as described below for each specifier. A conversion specification is executed in the following steps:

8 Input white-space characters (as specified by the isspace function) are skipped, unless the specification includes a [, c, or n specifier.

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