Open close principle in C#

Question

Pankaj Patel · Answer

Hi Naresh Beniwal Open Closed Principle (OCP) states that a class must be open to be extended but closed to changes. Example in C# is as following: BankAccount BankAccountBase SavingsAccount LongTermSavingsAccount BankAccount // Not following the Open Closed Principle public enum AccountType { SavingsAccount = 1 LongTermSavingsAccount = 2 } public class BankAcount { public string AccountNumber { get; set; } public string AccountTitle { get; set; } public AccountType BankAccountType { get; set; } public float CalculateInterest(float accountBalance) { // Add an IF statement for each type of new bank account -- violates OCP if (BankAccountType == AccountType.SavingsAccount) return accountBalance * 0.02F; if (BankAccountType == AccountType.LongTermSavingsAccount) return accountBalance * 0.04F; else return accountBalance; } } BankAccountBase // Following the Open Closed Principle public interface IBankAccount { float CalculateInterest(float accountBalance); } public abstract class BankAccountBase { public string AccountNumber { get; set; } public string AccountTitle { get; set; } public AccountType BankAccountType { get; set; } } SavingsAccount public class SavingsAccount : BankAccountBase IBankAccount { public float CalculateInterest(float accountBalance) { return accountBalance * 0.02F; } } LongTermSavingsAccount public class LongTermSavingsAccount : BankAccountBase IBankAccount { public float CalculateInterest(float accountBalance) { return accountBalance * 0.04F; } } How to use var bankAccount = new BankAcount() { AccountNumber = 100AAA AccountTitle = Mr. John Doe BankAccountType = AccountType.SavingsAccount }; Console.WriteLine($The Interest amount for {bankAccount.AccountTitle} is ${bankAccount.CalculateInterest(1000)}); //Calling class following Open Closed Principle var savingsBankAccount = new SavingsAccount() { AccountNumber = 100AAA AccountTitle = Mr. John Doe BankAccountType = AccountType.SavingsAccount }; Console.WriteLine($The Interest amount for {savingsBankAccount.AccountTitle} is ${savingsBankAccount.CalculateInterest(1000)}); Hope this will help you!

Aravind Govindaraj · Answer

The Open Close principle is one that is used to open extend and close for any changes. For eg. RBI has a set of norms and would like to extend the logic in SBI business cases. So we are extending the RBI library and changing in our SBI Library In this approach we are not modifying anything on Main placeholder however we are molding it in on required place on demand basis.

Nitin · Answer

https://www.c-sharpcorner.com/UploadFile/pranayamr/open-close-principle/

Vishal Yelve · Answer

The open-closed principle states that a software component like method class or module should be open for extension but closed for modification. Please check below links for your reference https://code-maze.com/open-closed-principle/ https://dotnettutorials.net/lesson/open-closed-principle/ https://levelup.gitconnected.com/4-ways-to-achieve-open-closed-principle-in-c-d2d0ebea4b86

Brahma Prakash Shukla · Answer

Example of open close principle- namespace SolidPrinciples.Open.Closed.Principle.After{ public abstract class Shape{ public abstract double Area(); } public class Rectangle: Shape{ public int Width { get; set; } public int Height { get; set; } public override double Area(){ return Width * Height; } } public class Circle : Shape{ public double Radius { get; set; } public override double Area(){ return Radius * Radius * Math.PI; } } public class CombinedAreaCalculator{ public double Area (Shape[] shapes){ double area = 0; foreach (var shape in shapes){ area += shape.Area(); } return area; } } }

Rajanikant Hawaldar · Answer

https://www.c-sharpcorner.com/article/solid-principles-in-c-sharp-open-closed-principle/ https://www.c-sharpcorner.com/blogs/open-close-principle-with-example1