语言：C； 单个scanf（）用于1或2个输入

Question

What's necessary:

Single scanf()* statement that can accommodate 2 types of input and assign them to before initialized variable/s.

*Or any other function/way that can do what's necessary.

Types of Input:

1. %c %i - Example: c 56
2. %c - Example: c

The Current Problem:

scanf("%c %i", &c, &i); - Must specify %i , however there are cases of no second argument %i .

Examples of possible input:

• c 567 (same line)

• i 21 (same line)

• h

Answer 1

you could read the line using fgets , then use sscanf which isn't interactive, count how many fields you've successfully parsed, and act accordignly:

#include <stdio.h>

int main()
{
 char buffer[100];
 char c;
 int i;

 fgets(buffer, sizeof(buffer), stdin);
 int nb_toks = sscanf(buffer,"%c %i", &c, &i);
 switch (nb_toks)
 {
 case 2:
    printf("%c %i\n",c,i);
    break;
 case 1:
    printf("%c\n",c);
    break;
 default:
   /* some error management */
 }

}