Problems in the Code

• SRP Violated: Single Responsibility Principle

• OCP Violated: Open/Closed Principle

(Other SOLID principles are not applicable yet.)

Why is SRP Violated?

• Account class handles:

  • Balance data

  • Interest calculation logic

• Two reasons to change = SRP violation.

SRP says: A class should have only one reason to change.

Why is OCP Violated?

• Adding new account types (e.g., "Premium") needs modifying CalculateInterest.

• Risk of introducing bugs while changing old code.

OCP says:

• Open for extension

• Closed for modification