输入输出函数

控制台输出函数 std::cout

#include <iostream>
int main()
{
    std::cout << "Hello world!\n";
    return 0;
}

多个输出项需要在一行显示的时候我们可以这样做：

#include <iostream>
int main()
{
    int x = 4;
    std::cout << "x is equal to: " << x;
    return 0;
} 

当我们需要打印的东西超过一行的时候，我们可以使用这个函数std::endl

#include <iostream>
int main()
{
    std::cout << "Hi!" << std::endl;
    std::cout << "My name is Alex." << std::endl;
    return 0;
}

个人理解：std::endl的作用类似于\n

控制台输入函数 std::cout

#include <iostream>
int main()
{
    std::cout << "Enter a number: "; // ask user for a number
    int x; // no need to initialize x since we're going to overwrite that value on the very next line
    std::cin >> x; // read number from console and store it in x
    std::cout << "You entered " << x << std::endl;
    return 0;
}