C++ Get Started

To start writing C++ code, you need just two things:

1. A C++ compiler — translates .cpp source into an executable.
2. A text editor or IDE — VS Code, CLion, Code::Blocks, or even Notepad.

Verify your install:

bash
g++ --version

You should see something like g++ (GCC) 13.2.0.

Step 1. Create a file hello.cpp:

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

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

Step 2. Compile:

bash
g++ hello.cpp -o hello

Step 3. Run:

bash
./hello       # macOS / Linux
hello.exe     # Windows

Hello, Codekilla!

• The compiler read hello.cpp.
• It translated the C++ into machine instructions for your CPU.
• It linked in the standard library (so cout works).
• It produced an executable binary called hello.

You don't need a runtime (like the JVM or Python interpreter) — the binary runs natively.

A safe default for learning:

bash
g++ -std=c++17 -Wall -g hello.cpp -o hello

1. Install VS Code.
2. Add the C/C++ extension by Microsoft.
3. Add Code Runner (optional, gives you a one-click ▶ Run button).
4. Open your folder, create hello.cpp, hit ▶ — you're coding.

Don't want to install anything? Use Codekilla's online C++ compiler — write code in the browser, click Run, see output. Perfect for learning on the go.

• Compiling but not running — g++ hello.cpp -o hello only creates the binary; you still need ./hello to execute.
• Wrong filename — Save as hello.cpp (not .c or .txt); .cpp is the standard extension.
• g++ not found — PATH not set after install. Restart the terminal or add the compiler's bin/ to PATH.
• Mixing tabs/spaces — Doesn't break C++ (it's not Python), but inconsistent indentation looks awful.
• Skipping -Wall — You'll miss bugs that the compiler could catch for free.

1. Install + compile — Set up g++ on your machine and compile hello.cpp. Confirm the binary runs. Hint: check version with g++ --version.
2. Filename change — Compile with g++ hello.cpp -o greeter and run ./greeter. Hint: name doesn't have to match source.
3. Add a warning — Add an unused variable like int x; and compile with -Wall. Hint: warning will say "unused variable x".
4. Print three lines — Modify the program to print 3 lines of your choice and re-run. Hint: 3 cout statements.

Think Like a Programmer: Master your toolchain first. Spending 30 minutes to set up g++ -Wall -std=c++17 saves you from days of confusing bugs later.