C语言: try to implement IndexOf function

Question

我尝试学习C 语言，但有些事情我不太清楚。我想编写 IndexOf 函数来搜索 string 中的字符并返回 Index 数字。我在 ubuntu 下运行它并使用它进行编译:

test1: test.c
    gcc -g -Wall -ansi -pedantic test.c -o myprog1

这是我尝试过的:

int c;
int result;

    printf("Please enter string: ");
    scanf("%s", str1);

    printf("Please enter char: ");
    scanf("%d", &c);

    result = indexof(str1, c);
    printf("Result value: %d\n", result);

这是我的职责:

int indexof(char *str, int c)
{
    int i;
    for (i = 0; i < strlen(str); i++)
    {
        if (str[i] == c)
            return i;
    }

    return -1;
}

所以我的问题是我的函数始终返回 -1

Answer 1

scanf("%c",&c)..您正在输入一个字符。

工作副本类似于:-

char c; // you want to find the character not some integer. 
int result;

printf("Please enter string: ");
scanf("%s", str1);

printf("Please enter char: ");
scanf("%d", &c);

result = indexof(str1, c);
printf("Result value: %d\n", result);

工作示例:-

#include <stdio.h>
#include <string.h>
 int indexof(char *str, char c)
    {
        int i;
        for (i = 0; i < strlen(str); i++)
        {
            if (str[i] == c)
                return i;
        }

        return -1;
    }

int main()
{
    char c;
    int result;
    char str1[100];

        printf("Please enter string: ");
        scanf("%s", str1);

        printf("Please enter char: ");
        scanf(" %c", &c);

        result = indexof(str1, c);
        printf("Result value: %d\n", result);

}