Notes

notes/4_01/inheritance.cpp

+#include <iostream>
+
+using namespace std;
+
+class shape {
+public:
+	int color;
+	virtual double area() = 0;
+	virtual double perimeter() = 0;
+	virtual ~shape() {};
+};
+
+class rectangle : public shape {
+private:
+	double width, height;
+public:
+	double area() {
+		return width * height;
+	}
+	double perimeter() {
+		return 2 *(width + height);
+	}
+	rectangle() {
+		width = 1;
+		height = 2;
+	}
+	rectangle(double width, double height) {
+		this->width = width;
+		this->height = height;
+	}
+	friend ostream &operator<<(ostream &o, const rectangle &r);
+};
+
+ostream &operator<<(ostream &o, const rectangle &r) {
+	return o << "Rectangle: Width " << r.width << ", Height " << r.height << endl;
+}
+
+class square : public shape {
+private:
+	double side;
+public:
+	double area() {
+		return side * side;
+	}
+	double perimeter() {
+		return 4 * side;
+	}
+	square() {
+		side = 1;
+	}
+	square(double side) {
+		this->side = side;
+	}
+	friend ostream &operator<<(ostream &o, const square &s);
+};
+
+ostream &operator<<(ostream &o, const square &s) {
+	return o << "Square: Side " << s.side << endl;
+}
+
+int main(int argc, char *argv[]) {
+	square s(4);
+	rectangle r(3, 5);
+	shape *sp = &s;
+	shape &sr = r;
+
+	cout << s << s.perimeter() << endl << s.area() << endl;
+	cout << r << r.perimeter() << endl << r.area() << endl;
+	cout << *sp;
+	cout << sr;
+
+	for (int i = 0; i < 10; i++) {
+		
+	}
+
+	return 0;
+}