Properties and Encapsulation
Before going on properties let’s have a look at why the concept of properties came into C#. This is because of two reasons: If the members of a class are private then how another class in C# will be able to read, write, or compute the value of that field?
If the members of the class are public then another class may misuse that member.
Properties in C# are members of a class, just like methods, fields, and events. They fall under the category of class members or object-oriented programming (OOP) concepts. Specifically, properties are a part of the encapsulation principle in OOP
Using a private variable with a public property instead of directly using a public variable has advantage:
Encapsulation and Data Hiding
By keeping the field private and using public property, you control how the data is accessed and modified. This is a key principle of encapsulation in object-oriented programming. It hides the internal implementation details and only exposes the necessary interface.
Example: Student Class with a Name Property
In this example, we’ll have a student class with a private field for the student’s name and a public property to access and modify that name.
using System;
public class Student
{
// Private field
private string name;
// Public property
public string Name
{
get { return name; } // Getter: retrieves the value
set { name = value; } // Setter: sets the value
}
}
public class Program
{
public static void Main()
{
// Create a new Student object
Student student = new Student();
// Use the property to set the name
student.Name = “John”;
// Use the property to get the name
Console.WriteLine(student.Name); // Output: John
}
}
Task:
1. Basic Property:
Create a class Rectangle with properties Length and Width. Add a method to calculate and return the area of the rectangle. Create an object of Rectangle in the Main method, set the properties, and print the area.
2. Read-Only Property:
Create a class Circle with a read-only property Radius and a method to calculate and return the circumference. Create an object of Circle in the Main method, set the radius through the constructor, and print the circumference.
3. Auto-Implemented Property:
Create a class Student with auto-implemented properties Name, Age, and Grade. Create an object of Student in the Main method, set the properties, and print them.
4. Property with Validation:
Create a class Employee with properties Name, Age, and Salary. Ensure that the Age property can only be set if the value is between 18 and 65. Create an object of Employee in the Main method, set the properties, and print them.
5. Static Property:
Create a class Counter with a static property Count that tracks the number of instances created. Increment the Count property in the constructor. Create multiple objects of Counter in the Main method and print the value of Count.
6. Calculated Property:
Create a class Temperature with a property Celsius and a read-only property Fahrenheit that returns the temperature in Fahrenheit. Create an object of Temperature in the Main method, set the Celsius property, and print both Celsius and Fahrenheit.
7. Private Set Property:
Create a class BankAccount with properties AccountNumber, Balance, and AccountHolder. The Balance property should have a private set accessor. Add methods to deposit and withdraw money. Create an object of BankAccount in the Main method, perform some transactions, and print the balance.
8. Property with Default Value:
Create a class Product with properties Name, Price, and Stock. The Stock property should have a default value of 100. Create an object of Product in the Main method, set the properties, and print them.
