Oop - Transperencies Ch 04

Chapter 04 Inheritance

Inheritance

A

A

B

B

C

1. Single

2. Multiple

A

A B

B

C

D

3. Hierarchical

4. Multilevel

A B

C

A D

B C

C

D

5. Hybrid

Object Oriented Programming (SYIF) 2008-2009 by Kute T. B.

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Chapter 04 Inheritance

Creating inheritance in C++ class derived-class : visibility-mode base-class { - - - - - // - - - - - // members of derived class - - - - - // }; private derivation: class ABC : private XYZ { members of ABC }; public derivation: class ABC : public XYZ { members of ABC }; default (private) derivation: class ABC : XYZ { members of ABC }; Object Oriented Programming (SYIF) 2008-2009 by Kute T. B.

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Chapter 04 Inheritance

class Maths { int a; public: int b; void get_ab( ) { a = 5; b = 10; } int get_a( ) { return(a); } void show_a( ) { cout<<"a="<
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Chapter 04 Inheritance

Multiple Inheritance B1

B2

Bn

D

class D : visibility B1, visibility B2 . . . { ----- - - - - // body of class D ----}; Example: class Maths: public Arith, public Geo { public: void display( ); } Object Oriented Programming (SYIF) 2008-2009 by Kute T. B.

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Chapter 04 Inheritance

class Geometry { protected: int m; public: void getM(int x) { m = x; } }; class Arithmetics { protected: int n; public: void getN(int x) { n = x; } }; class Maths : public Geometry, public Arithmetics { public: void displaySquare( ) { cout<<"\nSquare of m:"<<(m*m); cout<<"\nSquare of n:"<<(n*n); } }; int main( ) { Maths x; int a, b; cout<<"Enter two values: "; cin rel="nofollow">>a>>b; x.getM(a); x.getN(b); x.displaySquare( ); return(0); } Object Oriented Programming (SYIF) 2008-2009 by Kute T. B.

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Chapter 04 Inheritance

Hierarchical Inheritance Students

Arts

Engineering

Medical

class Students { // members of ‘Students’ }; class Arts : public Students { // members of ‘Arts’ }; class Engineering : private Students { // members of ‘Engineering’ }; class Medical : public Students { // members of ‘Medical’ }; Object Oriented Programming (SYIF) 2008-2009 by Kute T. B.

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Chapter 04 Inheritance

class Students { float marks; public: void getMarks(float test1, float test2) { marks = test1 + test2; cout<<"\nAverage: "<<(marks/2); } }; class Arts : private Students { public: void accept(float x, float y) { getMarks(x, y); } }; class Medical : private Students { public: void input(float x, float y) { getMarks(x, y); } }; int main( ) { Arts a; Medical m; a.accept(56.20, 85.14); m.input(63.42, 46.97); return(0); } Object Oriented Programming (SYIF) 2008-2009 by Kute T. B.

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Chapter 04 Inheritance

Hybrid Inheritance Students

Test

Result

Students

Sports

Test

Result

Sports

class Students { // - - - - }; class Test : public Students { // - - - - }; class Sports { // - - - - }; class Result : public Test, private Sports { // - - - - }; Object Oriented Programming (SYIF) 2008-2009 by Kute T. B.

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Chapter 04 Inheritance

class Students { protected: int roll; public: void getNumber(int n) { roll = n; } void putNumber() { cout<<"\nRoll: "<
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Chapter 04 Inheritance

void getScore(float s) { score = s; } void putScore() { cout<<"\nScore: "<<score; } }; class Result : public Test, public Sports { float total; public: void show() { total = test1 + test2; putNumber(); putMarks(); putScore(); cout<<"\nTotal: "<
Object Oriented Programming (SYIF) 2008-2009 by Kute T. B.

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Chapter 04 Inheritance

Virtual Base Class GrandFather

Parent1

Parent2

Child class A { // - - - - }; class B1 : virtual public A { // - - - - }; class B2 : public virtual A { // - - - - }; class C : public B1, public B2 { // - - - - }; Object Oriented Programming (SYIF) 2008-2009 by Kute T. B.

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Chapter 04 Inheritance

class Students { protected: int roll; public: void getNumber(int n) { roll = n; } void putNumber( ) { cout<<"\nRoll: "<
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Chapter 04 Inheritance

{ protected: float score; public: void getScore(float s) { score = s; } void putScore( ) { cout<<"\nScore: "<<score; } }; class Result : public Test, public Sports { float total; public: void show( ) { total = test1 + test2; putNumber( ); putMarks( ); putScore( ); cout<<"\nTotal: "<
Object Oriented Programming (SYIF) 2008-2009 by Kute T. B.

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Chapter 04 Inheritance

Constructors in the derived classes

Derived-constructor(arg1,arg2,…argn): Base-constructor-1(arg1), Base-constructor-2(arg3, arg2), ------Base-constructor-n(argn) { //body of derived constructor }

Object Oriented Programming (SYIF) 2008-2009 by Kute T. B.

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Chapter 04 Inheritance

Execution of base class Constructors

Method of inheritance class B : public A {

Order of execution A( ); B( );

}; class A : public B, public C B( { C( A( }; class A : public B, virtual public C C( { B( A( };

Object Oriented Programming (SYIF) 2008-2009 by Kute T. B.

//base //derived

); ); );

//base1 //base2 //derived

); ); );

//virtual base //base //derived

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Chapter 04 Inheritance

class Alpha { public: Alpha(int x) { cout<<"\nAlpha = "<<x; } }; class Beta { public: Beta(int y) { cout<<"\nBeta = "<
Object Oriented Programming (SYIF) 2008-2009 by Kute T. B.

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