C中的字数？

Question

所以当我编译这段代码时，我会得到比我应该多1个额外字符，有人请告诉我我正在做的愚蠢错误。

#include <stdio.h>
#include <conio.h>

int main() {
    char str[20];
    char A = 'a';
    char B = 'A';
    int count = 0, i;

    printf("Enter a string : ");
    fgets(str, 20, stdin);

    for (i = 0; str[i] != '\0'; i++) {
        if (str[i] == A||B)
            count++;
    }

    if (count == 0)
        printf("\nCharacter A is not present");
    else
        printf("\nThere are %d A's in your string.", count);
    getchar();

    return 0;
}

Answer 1

/ *这就是问题（str [i] == A）||（str [i] == B）* /

#include <stdio.h>
#include <conio.h>

int main() {
    char str[20];
    char A = 'a';
    char B = 'A';
    int count = 0, i;

    printf("Enter a string : ");
    fgets(str, 20, stdin);

    for (i = 0; str[i] != '\0'; i++) {
        if (str[i] == A || str[i] == B)
        count++;
    }

    if (count == 0)
        printf("\nCharacter A is not present");
    else
        printf("\nThere are %d A's in your string.", count);
    getchar();
    return 0;
}