C++ Introduction

C++ is a general-purpose, statically-typed, compiled programming language created by Bjarne Stroustrup in 1979 at Bell Labs. It started as "C with Classes" and grew into the most powerful systems language in production today.

In simple words:

• C++ is C with super-powers — adds object-oriented programming, templates, exceptions, and a huge standard library (STL).
• It compiles to fast native machine code — close to the metal, like C.
• Used everywhere performance matters: AAA games, browsers (Chrome, Firefox), operating systems, embedded systems, trading engines, robotics, ML libraries.

• Performance — among the fastest languages on Earth (within 1-5% of C).
• Memory control — pointers, references, RAII, smart pointers.
• OOP + Generic + Functional — supports all major paradigms.
• Massive ecosystem — STL, Boost, Qt, Unreal Engine, OpenCV.
• Interview gold — top product companies (Google, Meta, NVIDIA) test C++ heavily.
• B.Tech / CS coursework — DSA, Operating Systems, Compilers all use C++.

cpp Run in compiler
#include <iostream>
using namespace std;

int main() {
    cout << "Hello, Codekilla!" << endl;
    return 0;
}

Hello, Codekilla!

• #include <iostream> — pulls in the input/output stream library (so we can use cout).
• using namespace std; — saves us from typing std::cout every time.
• int main() { ... } — the entry point. Every C++ program must have exactly one main.
• cout << "..." << endl; — prints text; endl flushes the buffer and inserts a newline.
• return 0; — tells the OS the program exited cleanly.

• Forgetting #include <iostream> — cout won't be recognised.
• Using printf (C-style) but expecting C++ goodies — works, but mixing is ugly. Stick with cout for new code.
• Missing semicolons — every C++ statement ends with ;.
• Writing main without int return type — compilers are strict.
• Confusing << (stream insertion) with >> (extraction).

1. Hello world — Compile and run the snippet above with g++ hello.cpp -o hello && ./hello. Hint: needs g++ installed.
2. Multi-line output — Print three lines: your name, age, and favourite language using three cout statements. Hint: chain << or use multiple lines.
3. No namespace — Rewrite the program without using namespace std;. Hint: prefix std::cout and std::endl.
4. Spot the bug — Why doesn't this compile? cout << "Hi" Hint: missing ; and #include.

Think Like a Programmer: C++ rewards mastery of fundamentals — once you understand pointers, references and value semantics, every other language feels easy. Slow down on chapters 9–12; they unlock the rest.