C to C

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C to C Chapter 13 prepared by Ilker Korkmaz
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Moving from C to C

• C is not a pure object oriented programming
  language. C provides the programmers with both
  imperative programming and object oriented
  programming styles.
• It means that C programs can also be compiled
  with C compilers.
• Why do we need C?
• object oriented programming

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Why Object Oriented Design Approach?

• To implement the real world.
• The world consists of objects.
• A type of object includes the common members
  attributes and the methods.
• The attributes are the information data, whereas
  the methods are the behaviours.
• A class, which an object instantiates from, is
  the basic structure in the object-oriented world.
  The subclasses can be inherited from the base
  classes.
• At first, an object is to be constructed from a
  class, and at last the object is to be
  destructed.
• Above mentioned design approach is similar to the
  lives of the objects in the world.

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Object Oriented Programming

• Object oriented programming usually requires
  object oriented design.
• 3 main concepts of object oriented design ans so
  object oriented programming
• encapsulation
• inheritance
• polymorphism

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encapsulation

• to hide the information from irrelevant acces.
• 3 main properties to access to data
• private
• public
• protected

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inheritance

• A subclass (or child class), can be inherited
  from a super class (or base class, or parent
  class).
• The subclass objects inherit the common
  attributes and the common methods from their
  parents.

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polymorphism

• 2 main polymorhism styles
• compile-time polymorphism
• overloading
• The methods with the same names can be differed
  with different signatures.
• The operators can be overloaded.
• run-time polymorphism
• virtual methods
• Pure virtual methods in abstract base classes can
  be defined in different ways for different
  subclasses.

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Basics for moving from C to C
(I)

• source file
• source.c --gt source.cpp / source.C / source.cxx
• header file
• ltmath.hgt --gt ltcmathgt
• ltheader.hgt --gt ltcheadergt
• compiler
• gcc --gt g
• Every C source file can be compiled with a C
  compiler or with a C compiler. However, C
  source files can only be compiled with C
  compilers.

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Basics for moving from C to C
(II)

• standard I/O
• scanf --gt cin
• printf --gt cout
• ltstdio.hgt --gt ltiostreamgt
• using namespace std

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Basics for moving from C to C
(III)

• Reference
• type
• call-by-reference concept
• function(type) --gt
  function(type)
• void swap(int, int) --gt void swap(int,
  int)

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Basics for moving from C to C
(IV)

• The structure declarations of C source files are
  to be redesigned as the class declarations in
  C.
• struct ---gt class.
• The classes are the abstract data types, which
  ancapsulate the common attributes and provide the
  common methods for the objects to be instantiated.

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overloading

• method overloading
• double add(double, double)
• int add(int, int)
• operator overloading
• double operator(double, double)

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constructor/destructor

• constructor
• The special method of a class with the same name
  of the class.
• The constructor can be seen as the object
  initializing method that every class has to
  include either explicitly or implicitly.
• An object instantiates through its class's
  constructor method.
• Destructor
• Another special method of a class, which is
  automatically invoked when an object is destroyed.

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inheritance

• A new class can be implemented as a child of
  another existing class.
• A subclass inherits the common data of its
  parent(s).
• Good object oriented programming needs to use the
  inheritance properly.

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Examples

• First of all, how to write Hello World in
  C...
• Then, how to convert struct Student declaration
  into class Student declaration...
• Finally,
• How to declare a convenient Student abstract
  data type...
• How to use the encapsulation and the inheritance
  concepts through the Student class...
• ...