C++ 빅데이터 개발에서 데이터 형식 변환 문제를 해결하는 방법은 무엇입니까?

#include <iostream>
#include <string>

int main() {
    std::string str = "123";
    int num = std::stoi(str);
    std::cout << "转换后的数字为：" << num << std::endl;

    std::string strFloat = "3.14";
    float f = std::stof(strFloat);
    std::cout << "转换后的浮点数为：" << f << std::endl;

    return 0;
}

#include <iostream>
#include <string>

int main() {
    int num = 123;
    std::string str = std::to_string(num);
    std::cout << "转换后的字符串为：" << str << std::endl;

    float f = 3.14;
    std::string strFloat = std::to_string(f);
    std::cout << "转换后的字符串为：" << strFloat << std::endl;

    return 0;
}

#include <iostream>
#include <string>
#include <cstring>

int main() {
    std::string str = "hello";
    char charArray[10];
    std::strcpy(charArray, str.c_str());
    std::cout << "转换后的字符数组为：" << charArray << std::endl;

    char charArray2[10] = "world";
    std::string str2(charArray2);
    std::cout << "转换后的字符串为：" << str2 << std::endl;

    return 0;
}

#include <iostream>
#include <ctime>

int main() {
    std::time_t timestamp = std::time(nullptr);
    std::cout << "当前时间戳为：" << timestamp << std::endl;

    std::tm* timeinfo = std::localtime(&timestamp);
    char buffer[80];
    std::strftime(buffer, 80, "%Y-%m-%d %H:%M:%S", timeinfo);
    std::cout << "当前日期时间为：" << buffer << std::endl;

    return 0;
}