C# Object and classes
As we know, C# is an object oriented programming language, it provides oops concepts which are relevant to real world problems. C# Object: An object is a real world entity. It can be anything that exists in the real world and that has state and behavior for eg. Car, pen, chair, etc. In C#, object is a real time entity. It is an instance of the class which can access all the fields and methods of the class. Let's see an example of creating object of a class using new keyword. Student s=new student(); // creating object of student class Example illustrates the creation of object of student class. s is the reference variable to the object for which the memory is provided at runtime by new keyword. C# Class: In C#, class is the group of similar type of objects. A class can have static and non static methods. It can have fields and constructors. It represents the template of its object.
Let's see an example of C# class. public class student { int id; //integer field string name; //string field }C# Object and class Example:
using System; public class Employee { int id; string name; public static void Main (string[] args) { Employee emp=new Employee(); emp.id=100; emp.name="Ram Sharma"; Console.WriteLine(emp.name+" "+emp.id); } }Output
Ram Sharma 100C# Class and object Example: Accessing class data from another class
using System; public class Employee { public int id; public string name; public void display() { Console.WriteLine(id+" " +name); } } public class MainClass{ public static void Main (string[] args) { Employee emp=new Employee(); emp.id=100; emp.name="Ram Sharma"; emp.display(); } }Output
100 Ram SharmaC# Example: printing the class variables through method
using System; public class Employee { int id; string name; void display() { Console.WriteLine(id+" " +name); } public static void Main (string[] args) { Employee emp=new Employee(); emp.id=100; emp.name="Ram Sharma"; emp.display(); } }Output
100 Ram SharmaC# classes and objects Example : Initializing class data by a method
using System; public class Employee { public int id; public string name; public void setValues(int emp_id,string emp_name) { id=emp_id; name=emp_name; } public void display() { Console.WriteLine(id+" " +name); } } public class MainClass{ public static void Main (string[] args) { Employee emp=new Employee(); emp.setValues(200,"Harish Gupta"); emp.display(); } }Output
200 Harish GuptaC# Class and objects Examples: Storing and Retrieving information of various students
using System; public class Student { int roll_no; string name,course,batch; public void setValues(int student_roll_no,string student_name,string student_course,string student_batch) { roll_no=student_roll_no; name=student_name; course=student_course; batch=student_batch; } public void display() { Console.WriteLine(roll_no+" " +name+" "+course+" "+batch); } } public class MainClass{ public static void Main (string[] args) { Student s1=new Student(); s1.setValues(101,"Harish Gupta","B. Tech.","2016"); Student s2=new Student(); s2.setValues(102,"Ayush Sharma","B. Tech.","2017"); s1.display(); s2.display(); } }Output:
101 Harish Gupta B. Tech. 2016 102 Ayush Sharma B. Tech. 2017