Computer programming(C++): Structures

Computer programming(C++): Structures

• 1.
  C++ Structures 1
• 2.
  Sructure  Structure isa collection of variables of different data types under a single name. It is similar to a class in that, both holds a collection of data of different data types.  Structure definition struct tagname { data variable name 1 data variable name 2 ……………………………….. ……………………………….. }; 2
• 3.
  Array of structure Structure is collection of different data type. An object of structure represents a single record in memory, if we want more than one record of structure type, we have to create an array of structure or object. struct struct-name { datatype var1; datatype var2; - - - - - - - - - - - - - - - - - - - - datatype varN; }; struct-name obj [ size ]; 3
• 4.
  Files-Input & Output C++ comes with libraries which provides us many ways for performing input and output.  In C++ input and output is performed in the form of sequence of bytes or more commonly known as streams.  Input Stream: If the direction of flow of bytes is from device(for example: Keyboard) to the main memory then this process is called input.  Output Stream: If the direction of flow of bytes is opposite, i.e. from main memory to device( display screen ) then this process is called output. 4
• 5.
  Sequential and Randomacess  Sequential Access: The computer system reads or writes information to the file sequentially, starting from the beginning of the file and proceeding step by step.  It is faster than random access.  Random Access: The computer system can read or write information anywhere in the data file.  We can search through it and find the data we need more easily. 5
• 6.
  Object oriented programmings(Oops) Object-Oriented Programming is a methodology or paradigm to design a program using classes and objects.  It simplifies the software development and maintenance by providing some concepts. 6
• 7.
  Basic concepts ofOops  Object:  Any entity that has state and behavior is known as an object.  For example: chair, pen, table, keyboard, bike etc. It can be physical and logical.  Class:  Collection of objects is called class.  It is a logical entity.  It is a user defined data type. class class name { access_specifier_1: member1; access_specifier_2: member2; ... } object names; 7
• 8.
  Basic concepts ofOops  Class member function definitions  Inside of the class definition class class_name { private: declarations; public: function_declaration(parameters) { function_body; } }; 8
• 9.
  Basic concepts ofOops  Outside of the class definition return_type class_name::function_name(parameters) { function_body; } 9
• 10.
  Basic concepts ofOops  Data Abstraction:  Data abstraction is a concept which hides the background details and represents only the needed information to the outside world.  Data Encapsulation:  It is a technique which combines both data members and functions, operates on that data in a single unit known as a class.  Constructors:  Constructor is a member function with the same name as the name of a class.  It is used to initialize the objects of that class.  They don’t have any return type. 10
• 11.
  Basic concepts ofOops  Types of constructor  Default Constructor  A constructor without any parameters is called a default constructor.  Every instance of the class will be initialized to the same values.  Parameterized Constructor  A constructor with at least one parameter is called a parametrized constructor.  parametrized constructor is that you can initialize each instance of the class with a different value.  Copy Constructor  The constructor which creates an object by copying variables from another object is called a copy constructor.  It is to initialize a new instance to the values of an existing instance. 11
• 12.
  Basic concepts ofOops  Destructor:  Destructor is a member function which destructs or deletes an object.  A destructor has the same name as the class, preceded by a tilde (~).  Rules for Destructor:  Do not accept arguments.  Do not return a value (or void).  Inheritance:  It is basically a method which provides a way that capabilities and properties from one class to come into another class.  We can form a new class from an existing class.  Here the new class is called as the derived class and the existing class i.e. the class from which the new class is derived is called as the base class. 12
• 13.
  Basic concepts ofOops  Types of inheritance  Single Inheritance: In single inheritance, a class is allowed to inherit from only one class. i.e. one sub class is inherited by one base class only. 13
• 14.
   Multiple Inheritance:Multiple Inheritance is a feature of C++ where a class can inherit from more than one classes. i.e. one sub class is inherited from more than one base classes. 14
• 15.
   Multilevel Inheritance:In this type of inheritance, a derived class is created from another derived class. 15
• 16.
   Hybrid (Virtual)Inheritance: Hybrid Inheritance is implemented by combining more than one type of inheritance. 16
• 17.
   Hierarchical Inheritance:In this type of inheritance, more than one sub class is inherited from a single base class. i.e. more than one derived class is created from a single base class. 17