University:
Boston University
Course:
MET CS 201 | Introduction to Programming
Academic year:

2022
Views:

141

Pages:

6
Author:

Camilla House

Modify rectangle.h  As in the sample BasicRectangle, add storage for the length and width to the header file. Add a declaration for the Area method.  The protected keyword will be discussed later.  The private keyword declares anything following it (members, methods) to be visible only to code in this class. #ifndef RECTANGLE_H #define RECTANGLE_H class Rectangle { public: Rectangle(); virtual ~Rectangle(); float m_length ; float m_width ; float Area() ; protected: private: }; #endif // RECTANGLE_H Modify rectangle.cpp     This will now contain the code for the Area() method. Use the C::B environment to help out here! Open rectangle.cpp (under Sources/src) Right-click and choose Insert/All class methods without implementation   The Area() method is automatically found from the header file. Click OK. rectangle.cpp  The Area() method now has a basic definition added.  The syntax: class::method tells the compiler that this is the code for the Area() method declared in rectangle.h  Now take a few minutes to fill in the code for Area().  Hint – look at the code used in BasicRectangle... #include "rectangle.h" Rectangle::Rectangle() { //ctor } Rectangle::~Rectangle() { //dtor } float Rectangle::Area() { } More C::B assistance  You may have noticed C::B trying to help when entering the code for Area()  Press the Tab key to accept the suggestion  It will offer up variable names, member names, class names, etc. that match what you’re typing when appropriate to save you effort.  This can be a huge convenience when dealing with large code bases. Last Step      Go to the main.cpp file Add an include statement for “rectangle.h” Create a Rectangle object in main() Add a length and width Print out the area using cout.  Hint: just like the BasicRectangle example… Solution  You should have come up with something like this: #include using namespace std; #include "rectangle.h" int main() { Rectangle rT ; rT.m_width = 1.0 ; rT.m_length = 2.0 ; cout << rT.Area() << endl ; return 0; }