Object-Oriented Programming: Understanding Classes and Member Access, Slides of Object Oriented Programming

Download Object-Oriented Programming: Understanding Classes and Member Access and more Slides Object Oriented Programming in PDF only on Docsity! Object oriented programming (OOP) Lecture No. 7 docsity.com Class ►Class is a tool to realize objects ►Class is a tool for defining a new type docsity.com Type in C++ ►Mechanism for user defined types are  Structures  Classes ►Built-in types are like int, float and double ►User defined type can be  Student in student management system  Circle in a drawing software docsity.com Abstraction ►Only include details in the system that are required for making a functional system ►Student  Name  Address  Sibling  Father Business Relevant to our problem Not relevant to our problem docsity.com Defining a New User Defined Type class ClassName { … DataType MemberVariable; ReturnType MemberFunction(); … }; Syntax Syntax docsity.com Example Student aStudent; aStudent.rollNo = 514; aStudent.rollNo = -514; //Error docsity.com Object and Class ►Object is an instantiation of a user defined type or a class docsity.com Declaring class variables ►Variables of classes (objects) are declared just like variables of structures and built-in data types TypeName VaraibaleName; int var; Student aStudent; docsity.com Access specifiers docsity.com Access specifiers ►There are three access specifiers  ‘public’ is used to tell that member can be accessed whenever you have access to the object  ‘private’ is used to tell that member can only be accessed from a member function  ‘protected’ to be discussed when we cover inheritance docsity.com Example class Student{ private: char * name; int rollNo; public: void setName(char *); void setRollNo(int); ... }; Cannot be accessed outside class Can be accessed outside class docsity.com Example class Student { char * name; int RollNo; }; class Student { private: char * name; int RollNo; }; docsity.com Example class Student { char * name; int RollNo; void SetName(char *); }; Student aStudent; aStudent.SetName(Ali); Error docsity.com Example class Student { char * name; int RollNo; public: void setName(char *); }; Student aStudent; aStudent.SetName(“Ali”); docsity.com