Learn C# Object and Class - Concepts and Examples.

Classes and Objects

Imagine you have a box. This box is special because it can hold different things like toys, books, or anything you like. In programming, we have something similar called a “class.”

1. What is a Class?

A class is like a blueprint or plan for creating objects. Imagine you have a blueprint for building a house. It tells you what the house should look like and what rooms it should have. Similarly, a class tells the computer what properties and actions an object should have when it’s created.

Structure of Class

// Define a class
[access_modifier] class ClassName
{
    //Execution code like methods, fields , properties, constructor etc
}

2. What is an Object?

Now, imagine using that blueprint to create an actual car. That car you create is called an “object.”

An object is a real instance or copy of a class. It has unique properties (like the colour of the car) and behaviours (like driving or stopping).

Structure of Object

// Creating an object
ClassName objectName = new ClassName(parameters);// Accessing fields
objectName.fieldName = value;
// Calling methods
objectName.MethodName();

Example: Car Class and Objects

using System;
class Car
{
public string Colour;
public int Speed;
public void Drive(string colour , int speed)
{
Console.WriteLine(“The “+ colour +” car driving speed is ” + speed);
}
static void Main()
{
Car FirstCar = new Car();
FirstCar.Colour = “Red”;
FirstCar.Speed = 60;
Car SecondCar = new Car();
SecondCar.Colour = “Blue”;
SecondCar.Speed = 200;

FirstCar.Drive(FirstCar.Colour, FirstCar.Speed);
SecondCar.Drive(SecondCar.Colour,SecondCar.Speed);
}
}

Explanation

using System;

Define Simple class for the Car

class Car

Properties (attributes) of the car

public string Colour;
public int Speed;

Methods (actions) the car can do

public void Drive(string colour , int speed)
{
Console.WriteLine(“The “+ colour +” car driving speed is ” + speed);
}
static void Main()
{

Let’s create objects (instances) of the Car class:

Car FirstCar = new Car();

Creating a new car object

FirstCar.Colour = “Red”;

Setting the colour of the car

FirstCar.Speed = 60;

Setting the speed of the car

Car SecondCar = new Car();

Creating another car object to create second car

SecondCar.Colour = “Blue”;

Setting colour

SecondCar.Speed = 200;

Setting speed

Using the method of the car objects

FirstCar.Drive(FirstCar.Colour, FirstCar.Speed);

Output: The Red car driving speed is 60

SecondCar.Drive(SecondCar.Colour,SecondCar.Speed);

Output: The Blue car driving speed is 200

Course Video

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Task:

1. Create a class named Employee with the following properties:
string Name
int Id
double Salary
Create an object of the Employee class in the main method.
Assign values to the properties and print them to the console.

2. Create a class named Product with the following properties:
string ProductName
string Category
double Price
Create an object of the Product class in the main method.
Assign values to the properties and print them to the console.

3. Create a class named Student with the following properties:
string Name
int RollNumber
string Course
Create an object of the Student class in the main method.
Assign values to the properties and print them to the console.

4. Create a class named Car with the following properties:
string Make
string Model
int Year
Create an object of the Car class in the main method.
Assign values to the properties and print them to the console.

5. Create a class named Book with the following properties:
string Title
string Author
int Pages
Create an object of the Book class in the main method.
Assign values to the properties and print them to the console

C# Object and Class