intro to c++,need and applications

Fundamentals of OOP
 Class
 Object
 Encapsulation
 Abstraction
 Inheritance
 Polymorphism
 Reusability
C++ as an OOP language
 C++ : C with classes
 Multi-paradigm language
 As Object oriented language, it offers bottom to top approach
 As Procedural language, it offers top to bottom approach
Classes and objects (I)
 Class- user defined data type. Fundamental packaging unit of
OOP technology
 Class declaration is similar to struct declaration
 Keyword ‘class’ followed by class name.
 Object is an instance of class
 Object combines data and functions
 Object is created as a variable of class type using class name
 Members of class
 Data members / attributes
 Member functions / methods
Classes and objects (II)
 Structure of C++ program with class
Data members
 Data members can be any of the following types
 Primary data types : int, float, char, double, bool
 Secondary data types : arrays, pointers, class objects etc.
 Data members classified into two groups
 Regular : every object gets its own copy of data members
 Static: all objects share the same copy of data memberStatic Data Members
 Variable declaration preceded by keyword ‘static’
 Only one copy of static variable is created. All the objects share the same
copy
 Initialized to zero when first object is created. No other initialization
permitted.
 Should be defined outside the class definition after declaring them
inside the class in this way – datatype classname :: varname
 They are normally used to maintain values that are common to the
entire class, e.g., to keep a count of number of objects created.
Methods (I)
 Function defined inside a class declaration is called as
member function or method
 Methods can be defined in two ways - inside the class or
outside the class using scope resolution operator (::)
 When defined outside class declaration, function needs to be
declared inside the class
Methods (II)
Method defined inside the
class
Method defined outside
the class
Methods (III)
 Types of functions in a class
 Regular functions
 Overloaded functions
 Inline functions
 Friend functions
 Static functions
 Constructors
 Destructors
 Virtual functions