Input and output are how your program talks to the world. In C++, you use
cout to send text to the console and cin to read input
from the user. You also have endl to insert a new line and flush
the output buffer.
cout and cin
cout uses the << operator — think of it as an arrow
pointing toward cout, meaning data flows to the console.
cin uses the >> operator — data flows from the
keyboard into your variable.
The endl (end line) moves the cursor to the next line. You can also
use \n inside a string to do the same thing, but endl
also flushes the output, which can be helpful.
#include <iostream>
using namespace std;
int main() {
string name;
int age;
cout << "Enter your name: ";
cin >> name;
cout << "Enter your age: ";
cin >> age;
cout << "Hello, " << name << "!" << endl;
cout << "You are " << age << " years old." << endl;
cout << "Nice to meet you!";
return 0;
}
There is a catch with cin — it stops reading at whitespace. So if you
type "Bilal Mubarak" and press enter, only "Bilal" will be stored in the string.
To read a whole line including spaces, use getline(cin, variable) instead.
We will cover that in a later lesson.