c - 获取用户输入的第一个字符，丢弃 c 中的其余字符

Question

在我目前的代码中，如果用户输入的字符串不是以 c 或 s 开头，它将检查字符串中的每个字符，并继续输出 printf。我该怎么做才能让它只检查第一个字符并让用户输入一个新的字符串来检查。

#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
int main()
{
//Declare Variables
int players, P1, P2, P3, P4, loop, loop2;
char gameType;
char c;
//Initialize Variables
players = 0;
P1 = 0;
P2 = 0;
P3 = 0;
P4 = 0;
loop = 1;
loop2 = 1;

//Figure out what game type
printf("Commander or Standard?\n"); 
gameType = getchar();
    while (loop == 1)
    {   
        if (gameType == 'C' || gameType == 'c')
        {
            P1 = 40, P2 = 40, P3 = 40, P4 = 40;
            loop = 0;   
            printf("How many players?\n");
            scanf("%s", &players);
            printf("%c players\n", players);
        }
        else if (gameType == 'S' || gameType == 's')
        {
            P1 = 20, P2 = 20;
            printf("Player 1 HP: %d\n", P1);        
            printf("Player 2 HP: %d\n", P2);
            loop = 0;                   
        }
        else 
        {
            printf("Please enter either Commander or Standard\n");
            loop = 1;
            gameType = getchar();
        }
    }

return 0;
}   

Answer 1

您可以清除 printf 之前 else block 开头的输入。

while ( (gameType = getchar()) != '\n' && gameType != EOF ) { }