/*使用auto关键字，需要先赋初值，auto关键字是会根据初值来判断类型*/

    auto i = ;

    auto j = ;

    cout << "auto i = 5" << "\ti type:" << typeid(i).name() << endl << "auto j = 10" << "\tj type:" << typeid(j).name() << endl;

    cout << "i + j = " << i + j << endl;

    auto a = "Hello World!";

    cout << "auto a = Hello World!" << endl;

    cout << "a type:" << typeid(a).name() << endl;

    auto b = false;

    cout << "auto b = false" << endl;

    cout << "b type:" << typeid(b).name() << endl;