Structs (struct)

This lesson covers struct, used to bundle several pieces of data together. It's for anyone searching "C++ struct usage."

struct works very similarly to a class, letting you bundle multiple pieces of data into one type. The main difference from class in C++ is that a struct's members are public by default.

The example defines a struct, struct Point { double x; double y; };, and uses it to represent two coordinates.

A common early mistake is being unsure when to use struct versus class. A common convention: use struct when you just want to bundle plain data, and class when you want to attach a lot of behavior (member functions).

In real projects, structs are used to represent a simple bundle of data — a coordinate, an RGB color, a set of settings, and so on.

📖 Reference code

#include <iostream>
#include <cmath>

struct Point {
    double x;
    double y;
};

double distance(Point a, Point b) {
    return std::sqrt(std::pow(a.x - b.x, 2) + std::pow(a.y - b.y, 2));
}

int main() {
    Point p1 = {0, 0};
    Point p2 = {3, 4};
    std::cout << "Distance: " << distance(p1, p2) << std::endl;
    return 0;
}

✍️ Your code

Type your code, then press "Run"

🧪 This site can't compile or run C++ directly, so it checks on the spot whether what you typed matches the reference code (scoring happens entirely in your browser — nothing is sent anywhere).