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Ex Exampl ple:
#include "Cube.h" int main() { cs225::Cube c(10); c = c; return 0; } 1 2 3 4 5 6 7
Se Septembe ber 14 14 In Inheritance and Templates G G Carl - - PowerPoint PPT Presentation
Se Septembe ber 14 14 In Inheritance and Templates G G Carl - - PowerPoint PPT Presentation
Data Structures Se Septembe ber 14 14 In Inheritance and Templates G G Carl Evans Ex Exampl ple: assignmentOpSelf.cpp 1 #include "Cube.h" 2 3 int main() { 4 cs225::Cube c(10); 5 c = c; 6 return 0; 7 } Ex
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Ex Exampl ple:
#include "Cube.h" Cube& Cube::operator=(const Cube &other) { _destroy(); _copy(other); return *this; } 1 … 40 41 42 43 44 45 46
assignmentOpSelf.cpp
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In Inher erit itan ance ce
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#pragma once #include "Shape.h" class Square : public Shape { public: double getArea() const; private: // Nothing! };
Square.h
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Square.cpp
8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 … class Shape { public: Shape(); Shape(double length); double getLength() const; private: double length_; }; 4 5 6 7 8 9 10 11 12
Shape.h
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Der Deriv ived ed Clas lasses es
[Public Members of the Base Class]: [Private Members of the Base Class]:
int main() { Square sq; sq.getLength(); // Returns 1, the length init’d // by Shape’s default ctor ... } 5 6 7 8 … …
main.cpp
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Po Polymorphism
The idea that a single interface my take multiple types or that a single symbol may be different types. In Object-Orientated Programming (OOP) a key example is that a single
- bject may take on the type of any of its base types.
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Vi Virtua ual
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Cube.cpp
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 // No print_1() in RubikCube.cpp RubikCube::print_2() { cout << "Rubik" << endl; } // No print_3() in RubikCube.cpp RubikCube::print_4() { cout << "Rubik" << endl; } RubikCube::print_5() { cout << "Rubik" << endl; }
RubikCube.cpp
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Cube::print_1() { cout << "Cube" << endl; } Cube::print_2() { cout << "Cube" << endl; } virtual Cube::print_3() { cout << "Cube" << endl; } virtual Cube::print_4() { cout << "Cube" << endl; } // In .h file: virtual print_5() = 0;
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Ru Runtime of
- f V
Virt rtual F Function
- ns
virtual-main.cpp Cube c; RubikCube c; RubikCube rc; Cube &c = rc; c.print_1(); c.print_2(); c.print_3(); c.print_4(); c.print_5();
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Wh Why Polymorphism?
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class Animal { public: void speak() { } }; class Dog : public Animal { public: void speak() { } }; class Cat : public Animal { public: void speak() { } };
animalShelter.cpp
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Ab Abstract Cl Class:
[Requirement]: [Syntax]: [As a result]:
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class Cube { public: ~Cube(); }; class RubikCube : public Cube { public: ~RubikCube(); };
virtual-dtor.cpp
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class PNG { public: PNG(); PNG(unsigned int width, unsigned int height); PNG(PNG const & other); ~PNG(); PNG & operator= (PNG const & other); bool operator== (PNG const & other) const; bool readFromFile(string const & fileName); bool writeToFile(string const & fileName); HSLAPixel & getPixel(unsigned int x, unsigned int y) const; unsigned int width() const; // ... private: unsigned int width_; unsigned int height_; HSLAPixel *imageData_; void _copy(PNG const & other); };
MP2: cs225/PNG.h
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Ab Abstract D Data T Type
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Li List A ADT
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Wh What types of “stuff” do we want in our list?
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Te Templates
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T maximum(T a, T b) { T result; result = (a > b) ? a : b; return result; }
template1.cpp
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#pragma once class List { public: private: }; #endif
List.h
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List.cpp
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