如何将std :: string转换为int？

#include<iostream>
#include<string>

int main() {
    std::string str = "12345";
    int num = std::stoi(str);
    std::cout << "String: "<< str << ", Int: "<< num<< std::endl;
    return 0;
}

#include<iostream>
#include<string>

int main() {
    std::string str = "12345";
    try {
        int num = std::stoi(str);
        std::cout << "String: "<< str << ", Int: "<< num<< std::endl;
    } catch (const std::invalid_argument& e) {
        std::cout << "Invalid argument: " << e.what()<< std::endl;
    } catch (const std::out_of_range& e) {
        std::cout << "Out of range: " << e.what()<< std::endl;
    }
    return 0;
}