string类型转换int类型

C++转换形式(C++11):

 

 

int main(int argc, char* argv[]){        std::string str1 = "45";    std::string str2 = "3.14159";    std::string str3 = "31337 with words";    std::string str4 = "words and 2";    int myint1 = std::stoi(str1);    int myint2 = std::stoi(str2);    int myint3 = std::stoi(str3);    // error: 'std::invalid_argument'     /*int myint4 = std::stoi(str4);*/    std::cout << "std::stoi(\"" << str1 << "\") is " << myint1 << '\n';    std::cout << "std::stoi(\"" << str2 << "\") is " << myint2 << '\n';    std::cout << "std::stoi(\"" << str3 << "\") is " << myint3 << '\n';    /*std::cout << "std::stoi(\"" << str4 << "\") is " << myint4 << '\n';*/}

 

output:

 

std::stoi("45") is 45std::stoi("3.14159") is 3std::stoi("31337 with words") is 31337

 

 

 

同样, 可以使用 stol(long), stof(float), stod(double) 等.