Camp 1 · Schritt 2 von 12
Hello, World!
Run C++ and understand streams — the << and >> style that defines its input and output.
C++ prints differently from most languages, using streams. Odd at first, elegant once it clicks.
The program
Decoded
#include <iostream> — the input/output stream library,
providing cout and cin.
std::cout — the "character output" stream (your screen). std:: is
its namespace — the standard library lives under std:: to avoid name
clashes.
<< — the stream insertion operator. Picture data flowing into the
stream in the arrow's direction: cout << "Hello" pushes text out. Chain
them: cout << a << b << c.
std::endl — ends the line (like \n) and flushes the output.
Reading input with cin
The mirror image uses >> and the cin stream:
int age;
std::cout << "Your age? ";
std::cin >> age; // arrow points INTO the variable
std::cout << "Next year: " << age + 1 << std::endl;The arrows tell the story: << pushes out to cout, >> pulls in
to your variable from cin. Direction = data flow.
In std::cout << "Hi"; which way does data flow?
What is std:: in std::cout?
What's next
Variables and types — the core language, shared with C but with C++ comforts.