//A very simple class
#include<iostream>
using namespace std;
//Rectangle class declaration
class Rectangle {
    private:
        double width; 
        double length;
    public: 
        Rectangle();  //constructor
        Rectangle(double, double); //constructor
        void setWidth(double);
        void setLength(double);
        double getWidth() const;
        double getLength() const;
        double area() const;
};
Rectangle::Rectangle() {
    width=1;
    length=1;
} //constructor
Rectangle::Rectangle(double w, double l) {
    width=w;
    length=l;
} //constructor
void Rectangle::setWidth(double w) {
    width=w;
} //setWidth
void Rectangle::setLength(double l) {
    length=l;
} //setLength
double Rectangle::getWidth() const{
    return width;
} //getWidth
double Rectangle:: getLength() const{
    return length;
} //getWidth
double Rectangle::area() const{
    return width*length;
} //getArea
int main() {
    Rectangle box;  //box is an instance of Rectangle class
    box.setWidth(5); //set member attribute width
    box.setLength(8); //set member attribute length
    Rectangle crate;  //crate is an instance of Rectangle class 1x1
    Rectangle carton(3,6); //carton is declared using constructor 3x6
    cout<<"Area of box is "<<box.area()<<endl;  //prints 40
    cout<<"Area of carton is "<<carton.area()<<endl; //prints 18
    cout<<"Area of crate is "<<crate.area()<<endl; //prints 1
    system("pause");
    return 0;
} //main