Levels of Inheritance Multiple Inheritance Malik Jahan Khan

Levels of Inheritance • Classes can be derived from the classes that are themselves

• Recall the Employee example, just discussed in previous class • We introduce

class foreman : public laborer //foreman class { private: float quotas; //percent of quotas

int main() { laborer l 1; foreman f 1; cout << endl; cout <<

Multiple Inheritance • A class may inherit from more than one parent classes 6

#include <iostream> #include <string> using namespace std; class student //educational background { private: string

class employee { private: string name; //employee name unsigned long number; //employee number public:

class manager : private employee, private student //management { private: string title; //"vice-president" etc.

class scientist : private employee, private student //scientist { private: int pubs; //number of

class laborer : public employee { }; //laborer 11

int main() { manager m 1; scientist s 1, s 2; laborer l 1;

Ambiguity in Multiple Inheritance #include <iostream> using namespace std; class A { public: void

Graphics Example • Self-reading assignment • Implement and understand this example yourselves from textbook

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Levels of Inheritance + Multiple Inheritance Malik Jahan Khan 1

Levels of Inheritance • Classes can be derived from the classes that are themselves derived • Example class A {}; class B : public A {}; class C: public B {}; 2

• Recall the Employee example, just discussed in previous class • We introduce a new class named as “foreman” – Foreman is a head laborer who oversees how many products have been produced by his team 3

class foreman : public laborer //foreman class { private: float quotas; //percent of quotas met successfully public: void getdata() { laborer: : getdata(); cout << " Enter quotas: "; cin >> quotas; } void putdata() const { laborer: : putdata(); cout << "n Quotas: " << quotas; } }; 4

int main() { laborer l 1; foreman f 1; cout << endl; cout << "n. Enter data for laborer 1"; l 1. getdata(); cout << "n. Enter data foreman 1"; f 1. getdata(); cout << endl; cout << "n. Data on laborer 1"; l 1. putdata(); cout << "n. Data on foreman 1"; f 1. putdata(); cout << endl; return 0; } 5

Multiple Inheritance • A class may inherit from more than one parent classes 6

#include <iostream> #include <string> using namespace std; class student //educational background { private: string school; //name of school or university string degree; //highest degree earned public: void getedu() { cout << " Enter name of school or university: "; cin >> school; cout << " Enter highest degree earned n"; cout << " (Highschool, Bachelor's, Master's, Ph. D): "; cin >> degree; } void putedu() const { cout << "n School or university: " << school; cout << "n Highest degree earned: " << degree; } }; 7

class employee { private: string name; //employee name unsigned long number; //employee number public: void getdata() { cout << "n Enter last name: "; cin >> name; cout << " Enter number: "; cin >> number; } void putdata() const { cout << "n Name: " << name; cout << "n Number: " << number; } }; 8

class manager : private employee, private student //management { private: string title; //"vice-president" etc. double dues; //golf club dues public: void getdata() { employee: : getdata(); cout << " Enter title: "; cin >> title; cout << " Enter golf club dues: "; cin >> dues; student: : getedu(); } void putdata() const { employee: : putdata(); cout << "n Title: " << title; cout << "n Golf club dues: " << dues; student: : putedu(); } }; 9

class scientist : private employee, private student //scientist { private: int pubs; //number of publications public: void getdata() { employee: : getdata(); cout << " Enter number of pubs: "; cin >> pubs; student: : getedu(); } void putdata() const { employee: : putdata(); cout << "n Number of publications: " << pubs; student: : putedu(); } }; 10

class laborer : public employee { }; //laborer 11

int main() { manager m 1; scientist s 1, s 2; laborer l 1; cout << endl; cout << "n. Enter data for manager 1"; //get data for m 1. getdata(); //several employees cout << "n. Enter data for scientist 1"; s 1. getdata(); cout << "n. Enter data for scientist 2"; s 2. getdata(); cout << "n. Enter data for laborer 1"; l 1. getdata(); cout << "n. Data on manager 1"; //display data for m 1. putdata(); //several employees cout << "n. Data on scientist 1"; s 1. putdata(); cout << "n. Data on scientist 2"; s 2. putdata(); cout << "n. Data on laborer 1"; l 1. putdata(); cout << endl; return 0; } 12

Ambiguity in Multiple Inheritance #include <iostream> using namespace std; class A { public: void show() { cout << "Class An"; } }; class B { public: void show() { cout << "Class Bn"; } }; class C : public A, public B { }; int main() { C obj. C; //object of class C obj. C. show(); //ambiguous--will not compile obj. C. A: : show(); //OK obj. C. B: : show(); //OK return 0; 13

Graphics Example • Self-reading assignment • Implement and understand this example yourselves from textbook 14

• • • • • • • • • • • • • • • • • • • • • // multshap. cpp // balls, rects, and polygons #include "msoftcon. h" //for graphics functions //////////////////////////////// class shape //base class { protected: int x. Co, y. Co; //coordinates of shape color fillcolor; //color fstyle fillstyle; //fill pattern public: //no-arg constructor shape() : x. Co(0), y. Co(0), fillcolor(c. WHITE), fillstyle(SOLID_FILL) { } //4 -arg constructor shape(int x, int y, color fc, fstyle fs) : x. Co(x), y. Co(y), fillcolor(fc), fillstyle(fs) { } void draw() const //set color and fill style { set_color(fillcolor); set_fill_style(fillstyle); } }; //////////////////////////////// class circle : public shape { private: int radius; //(x. Co, y. Co) is center public: circle() : shape() //no-arg constr { } //5 -arg constructor circle(int x, int y, int r, color fc, fstyle fs) : shape(x, y, fc, fs), radius(r) { } void draw() const //draw the circle { shape: : draw(); draw_circle(x. Co, y. Co, radius); } }; //////////////////////////////// class rect : public shape { private: int width, height; //(x. Co, y. Co) is upper left corner public: rect() : shape(), height(0), width(0) //no-arg ctor { } //6 -arg ctor rect(int x, int y, int h, int w, color fc, fstyle fs) : shape(x, y, fc, fs), height(h), width(w) { } void draw() const //draw the rectangle { shape: : draw(); draw_rectangle(x. Co, y. Co, x. Co+width, y. Co+height); set_color(c. WHITE); //draw diagonal draw_line(x. Co, y. Co, x. Co+width, y. Co+height); } }; //////////////////////////////// class tria : public shape { private: int height; //(x. Co, y. Co) is tip of pyramid public: tria() : shape(), height(0) //no-arg constructor {} //5 -arg constructor tria(int x, int y, int h, color fc, fstyle fs) : shape(x, y, fc, fs), height(h) { } void draw() const //draw the triangle { shape: : draw(); draw_pyramid(x. Co, y. Co, height); } }; //////////////////////////////// int main() { init_graphics(); //initialize graphics system • • • circle cir(40, 12, 5, c. BLUE, X_FILL); //create circle rect rec(12, 7, 10, 15, c. RED, SOLID_FILL); //create rectangle tria tri(60, 7, 11, c. GREEN, MEDIUM_FILL); //create triangle • • cir. draw(); //draw all shapes rec. draw(); tri. draw(); set_cursor_pos(1, 25); //lower left corner 15