int my_str_len(const char* p_char)
    {
        int num = 0;
        if (NULL == p_char)
        {
            return 0;
        }
        while(*p_char)
        {
            p_char++;
            num++;
        }
        return num;
    }

    int my_str_len(const char* p_char)
    {
        if (NULL == p_char)
        {
            return 0;
        }

        const char *p_head = p_char;
        while(*p_char++);
        return p_char - p_head - 1;
    }