如何在c中一次从一串没有空格的字符中取出一个字符作为输入？

假设“5181 2710 9900 0012”是一串数字。我需要一次从没有空格的数字串中取出一个数字作为输入来进行算术运算。所以，我写的是，

int a[20];
for(int i=0;i<16;i++)
{
scanf("%d",&a[i]);
  }

但它没有给我预期的结果。但是当我使用“%1d”而不是“%d”时，它给了我预期的结果。那么，它是如何运作的呢？

Since scanf is the inverse of printf, you could verify this by printing any number with the modifier (just a little tip).*

一般来说，格式之前的数字是“宽度”修饰符。在这种情况下，这意味着您只将一个字节读入一个数字。如果指定%d，则它可以是任意长度的数字。

Example:

#include <stdio.h>

int main() {
    int a;
    sscanf("1234", "%d", &a);
    printf("%d\n", a); // prints 1234
    sscanf("1234", "%1d", &a); 
    printf("%d\n"m a); // prints 1
}

---

*) this appears to be false for this particular case. Makes sense that numbers are not truncated when specifiying a %d format, though, since that would change the meaning of the number. However, for many cases you could try what printf would do to predict scanf's behavior. But of course, reading the manual or docs on it is always the more helpful approach :)