scanf() 将字符添加到字符串

Question

我有这段代码，当我比较它们时，它会不断地将猜测字符串添加到单词字符串中，导致它们永远不会相同。我该如何解决这个问题？

#include <string.h> 

int main() {
    char wordle[5];
    char guesses[5];
    int guess = 5;
    int value;
   
    printf("Please input a secret 5 letter word:\n");
    scanf("%s",wordle);
    

    
    while (guess != 0){
        printf("You have %d tries, please guess the word\n",guess);
        scanf("%s",guesses);
        
        value = strcmp(wordle,guesses);
        
        if (value == 0){
            printf("you win\n");
            break;
        }
        guess = guess - 1;
    }
  
    return 0;
}```

Answer 1

您的程序有未定义的行为。你犯了两个错误。

1. 如果您的用户输入 5 个字符，则需要 6 个字符来存储该字符串。该程序将尝试将空终止符写入 wordle[5]，这不是有效的索引。

2. 您的用户可以输入任意数量的字母。您需要确保它们不会溢出您的缓冲区。

#include <stdio.h>
#include <string.h>

int main() {
    char wordle[6];
    char guesses[6];
    int guess = 5;
    int value;

    int chars_read;
    do {
        printf("Please input a secret 5 letter word:\n");
        chars_read = scanf("%5s%*s\n", wordle);
    } while(chars_read != 1 && strlen(wordle) != 5);
    
    while (guess != 0){
        do {
            printf("You have %d tries, please guess the word\n", guess);
            chars_read = scanf("%5s%*s\n", guesses);
        } while(chars_read != 1 && strlen(wordle) != 5);
        
        value = strcmp(wordle, guesses);
        
        if (value == 0){
            printf("you win\n");
            break;
        }
        guess = guess - 1;
    }
  
    return 0;
}

查看实际操作

scanf、fscanf、sscanf、scanf_s、fscanf_s、sscanf_s

MSC24-C 。不要使用已弃用或过时的函数

Answer 2

您的单词和猜测字符串太短。您需要为“\0”腾出空间。它们的长度应该是 6 个字节而不是 5 个字节。

char wordle[6];
char guesses[6];