19 CLASSES vs STRUCTS in C++

structure (struct) and class are essentially the same with minimal differences.

1. The Only Difference

struct defaults to public access.

struct Player
{   
    int x, y;
    int speed;
};


int main()
{
    Player player;
    player.x = 5;   // No compilation error
    std::cin.get();
}

struct Player  // Setting private attributes
{   
private:
    int x, y;
    int speed;
};

int main()
{
    Player player;
    player.x = 5;   // Compilation error
    std::cin.get();
}

2. Usage Differences

Functionally, there is not much difference, but there are distinctions in actual code usage.

The only reason struct exists in C++ is to maintain compatibility with C, as C does not have class.

The choice between using struct or class is subjective and depends on individual programming style. For example, use struct if you want default public access.

Cherno's Idea

struct: Used only to represent some data, absolutely no inheritance.

struct Vec2
{
    float x, y;

    void Add(const Vec2& other)
    {
        x += other.x;
        y += other.y;
    }
};

class: Classes with many functionalities, possibly involving inheritance.