Minimal Introduction to C++ - Part III - Final. C++ (pronounced "see plus plus") is a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language. It is regarded as an intermediate-level language, as it comprises both high-level and low-level language features. Developed by Bjarne Stroustrup starting in 1979 at Bell Labs, C++ was originally named C with Classes, adding object oriented features, such as classes, and other enhancements to the C programming language.

1. Universidade Federal de Alagoas :: Campus A. C. Simões Geometric Modeling and Computer Vision Laboratory
Minimal Introduction to C++
A Approach Directed to Resolution of Practical Problems
Michel Alves dos Santos
Universidade Federal de Alagoas, Campus A. C. Simões
Tabuleiro do Martins - Maceió - AL, CEP: 57072-970
Part III - Mechanisms of Inheritance and Polymorphism
{michel.mas}@gmail.com
February 14, 2013
Minimal Introduction to C++ Language - Michel Alves A Approach Directed to Resolution of Pratical Problems

2. Universidade Federal de Alagoas :: Campus A. C. Simões Geometric Modeling and Computer Vision Laboratory
Inheritance and Polymorphism
Mechanisms of Inheritance and Polymorphism
What happens in this figure?
Minimal Introduction to C++ Language - Michel Alves A Approach Directed to Resolution of Pratical Problems

3. Universidade Federal de Alagoas :: Campus A. C. Simões Geometric Modeling and Computer Vision Laboratory
What is Inheritance?
The Concept of Inheritance
Inheritance is a mechanism of reusing and extending
existing classes without modifying them, thus
producing hierarchical relationships between them.
§ ¤
1 c l a s s Polygon { /∗Some code . . . ∗/ };
2 c l a s s T r i a n g l e : p u b l i c Polygon { /∗Some code . . . ∗/ };
3 c l a s s Rectangle : p u b l i c Polygon { /∗Some code . . . ∗/ };
¦ ¥
Minimal Introduction to C++ Language - Michel Alves A Approach Directed to Resolution of Pratical Problems

4. Universidade Federal de Alagoas :: Campus A. C. Simões Geometric Modeling and Computer Vision Laboratory
What is Polymorphism?
The Concept of Polymorphism
Polymorphism is the ability of objects belonging to
different types to respond to method, field, or
property calls of the same name, each one according
to an appropriate type-specific behavior.
Entities that have more than one form.
§ ¤
1 /∗ Example : the + ( p l u s ) o p e r a t o r i n C++∗/
2
3 4 + 5 // i n t e g e r a d d i t i o n
4 3.14 + 2.0 // f l o a t i n g p o i n t a d d i t i o n
5 " foo " + " bar " // s t r i n g c o n c a t e n a t i o n !
6
7 /∗ In C++, that type of polymorphism i s c a l l e d o v e r l o a d i n g ∗/
¦ ¥
Polymorphism means that some code or operations or objects behave differently in different
contexts.
Minimal Introduction to C++ Language - Michel Alves A Approach Directed to Resolution of Pratical Problems

5. Universidade Federal de Alagoas :: Campus A. C. Simões Geometric Modeling and Computer Vision Laboratory
Inheritance and Polymorphism: Examples
Some Examples of Inheritance and Polymorphism
What is the importance of abstract classes?
Minimal Introduction to C++ Language - Michel Alves A Approach Directed to Resolution of Pratical Problems

6. Universidade Federal de Alagoas :: Campus A. C. Simões Geometric Modeling and Computer Vision Laboratory
Polymorphism in C++
Types of Polymorphism in C++
• Subtype Polymorphism (Runtime Polymorphism).
• Parametric Polymorphism (Compile-Time Polymorphism).
• Ad-hoc Polymorphism (Overloading).
• Coercion Polymorphism (Casting).
Minimal Introduction to C++ Language - Michel Alves A Approach Directed to Resolution of Pratical Problems

7. Universidade Federal de Alagoas :: Campus A. C. Simões Geometric Modeling and Computer Vision Laboratory
Polymorphism in C++: Code Example
Code Example
§ ¤
1 /∗ Base c l a s s ∗/
2 c l a s s F e l i d { p u b l i c : v i r t u a l v o i d meow( ) = 0 ; };
3
4 /∗ S u b c l a s s e s ∗/
5 c l a s s Cat : p u b l i c F e l i d { p u b l i c : v o i d meow( ) { cout << "meow! n" ; }};
6 c l a s s Tiger : p u b l i c F e l i d { p u b l i c : v o i d meow( ) { cout << "MREOW! n" ; }};
7 c l a s s Ocelot : p u b l i c F e l i d { p u b l i c : v o i d meow( ) { cout << "mews! n" ; }};
¦ ¥
§ ¤
1 template <c l a s s T> T max(T a , T b ) { r e t u r n a > b ? a : b ;}
2
3 i n t main ( )
4 {
5 std : : cout << max (9 , 5) << " t " << max( " foo " , " bar " ) << std : : e ndl ; // 9 foo
6 r e t u r n 0 ;
7 }
¦ ¥
§ ¤
1 3.14 + 2.0 // f l o a t i n g p o i n t a d d i t i o n
2 " foo " + " bar " // s t r i n g c o n c a t e n a t i o n !
¦ ¥
§ ¤
1 f l o a t b = 6 ; // i n t g et s promoted ( c a s t ) to f l o a t i m p l i c i t l y
2 i n t a = 9.99 // f l o a t g et s demoted to i n t i m p l i c i t l y
¦ ¥
Minimal Introduction to C++ Language - Michel Alves A Approach Directed to Resolution of Pratical Problems

8. Universidade Federal de Alagoas :: Campus A. C. Simões Geometric Modeling and Computer Vision Laboratory
Solved Problems
A List of Solved Problems
1 The Hierarchy of Polygon Class.
• Build a system that can represent the hierarchy of
polygons. The base action of this hierarchy must
be area.
2 The Area of Any Function or Curve j.
• Build a program that can calculate the area of any
function or curve using the methods of rectangle
and trapezium.
Minimal Introduction to C++ Language - Michel Alves A Approach Directed to Resolution of Pratical Problems

9. Universidade Federal de Alagoas :: Campus A. C. Simões Geometric Modeling and Computer Vision Laboratory
Exercises to Home
• Problem: The Hierarchy of Sorting Algorithms
• Build a minimal system that can represent the
hierarchy of sorting algorithms considering ours
complexity.
• Algorithms that must be implemented: bubble, insertion, quick and merge.
• Polyhedron Representation
• Build a minimal system that can represent
regular polyhedrons. The base class
Polyhedron must has the follow methods:
• is_regular, area, volume, edge_length.
Minimal Introduction to C++ Language - Michel Alves A Approach Directed to Resolution of Pratical Problems

10. Universidade Federal de Alagoas :: Campus A. C. Simões Geometric Modeling and Computer Vision Laboratory
Thanks
Thanks for your attention!
Michel Alves dos Santos - michel.mas@gmail.com
Minimal Introduction to C++ Language - Michel Alves A Approach Directed to Resolution of Pratical Problems