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Hello, C++

Welcome to C++. Bjarne Stroustrup started it in 1979 as "C with Classes" and renamed it C++ in 1983, and almost everything you learned in C still works: variables, if, loops, functions, pointers, arrays and structs. What C++ adds are tools that make programs safer and shorter: classes that clean up after themselves, a huge standard library (strings, dynamic arrays, maps, algorithms), references, templates and more.

The first difference you'll notice is output. Instead of printf with format specifiers, C++ uses streams:

#include <iostream>

int main() {
    int kills = 25;
    double accuracy = 0.61;
    std::cout << "Kills: " << kills << "\n";
    std::cout << "Accuracy: " << accuracy << " (" << accuracy * 100 << "%)\n";
}

Kills: 25
Accuracy: 0.61 (61%)

How it works

• #include <iostream> brings in the stream library (C++ standard headers have no .h).
• std::cout is the standard output stream, the C++ equivalent of stdout.
• << sends a value into the stream. Expressions chain from left to right: each << returns the stream again, so the next << continues writing.
• There are no format specifiers. The compiler knows each value's type and picks the right way to print it, so the classic printf mismatch bugs can't happen.
• std:: is a namespace prefix: the standard library's names live in the namespace std, so they don't clash with your own names.
• In C++, main may leave out return 0;; reaching the end of main means success.

You'll see std::endl in older code; it prints a newline and flushes the stream, which is slower. "\n" is usually what you want.

Your turn: print Rounds won: 13 using cout.

Next: Reading with cin