C++ (gcc-9.2) Compiler Online & Editor

Online C++ Compiler

This online C++ compiler lets you write, compile and execute C++ programs directly in your browser. It supports C++ 17.0 and uses GCC for compilation — the same compiler used in professional software development. No installation, configuration, or signup is required.

Whether you are learning object-oriented programming, practising data structures and algorithms, or testing a quick algorithm idea, this online C++ IDE gives you a complete development environment in seconds.

About C++ Programming

C++ is a general-purpose programming language created by Bjarne Stroustrup as an extension of C. It adds object-oriented programming, templates, exception handling, and the Standard Template Library (STL) while retaining full C compatibility. C++ is one of the most powerful and widely used programming languages in the world.

C++ is used in game engines (Unreal Engine), operating systems (parts of Windows), browsers (Chrome's rendering engine Blink), high-frequency trading systems, scientific computing, and anywhere that performance is critical. C++17, used in this compiler, introduced structured bindings, if constexpr, parallel algorithms, and many other modern features.

Key Features of C++

• Object-oriented programming: Classes, inheritance, polymorphism, and encapsulation make it easier to model complex real-world systems.
• Templates and generics: Write type-safe, reusable code with C++ templates and the Standard Template Library.
• RAII and smart pointers: Modern C++ manages memory safely without garbage collection, using deterministic resource cleanup.
• Performance: C++ compiles to native machine code with no virtual machine overhead, making it one of the fastest languages available.
• STL: A rich standard library providing vectors, maps, algorithms, iterators, and more — ready to use without extra setup.
• Backward compatibility with C: Existing C code can be used directly in C++ projects.

C++ Code Examples

Classes and Objects

#include <iostream>
using namespace std;

class Rectangle {
    int width, height;
public:
    Rectangle(int w, int h) : width(w), height(h) {}
    int area() { return width * height; }
};

int main() {
    Rectangle r(10, 5);
    cout << "Area: " << r.area() << endl;
    return 0;
}

Vectors and STL

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main() {
    vector<int> v = {5, 3, 1, 4, 2};
    sort(v.begin(), v.end());

    for (int x : v) {
        cout << x << " ";
    }
    cout << endl;
    return 0;
}

Inheritance and Polymorphism

#include <iostream>
using namespace std;

class Animal {
public:
    virtual void speak() { cout << "..." << endl; }
};

class Dog : public Animal {
public:
    void speak() override { cout << "Woof!" << endl; }
};

class Cat : public Animal {
public:
    void speak() override { cout << "Meow!" << endl; }
};

int main() {
    Animal* animals[] = { new Dog(), new Cat() };
    for (auto a : animals) a->speak();
    return 0;
}

Why Learn C++?

C++ is consistently ranked among the top five most-used programming languages worldwide. It is the language of choice for game development, systems programming, embedded software, and any domain where raw performance matters. Learning C++ after C is a natural progression — start with the fundamentals using our online C compiler, then move to C++ when you are ready for classes, templates, and the STL.