C++: What is the difference between struct and class in C++?

In C++, the only difference is the default access modifier.

struct:

• Default: public members.
• Default: public inheritance.

class:

• Default: private members.
• Default: private inheritance.

1struct Point {
2    int x;  // public by default
3    int y;
4};
5
6class Point2 {
7    int x;  // private by default
8    int y;
9public:
10    void setX(int x) { this->x = x; }
11};

Convention:

• struct — for passive data structures (POD).
• class — for objects with behavior.