C# Abstraction
C# Abstraction
Abstraction in C# is an OOP concept that hides the implementation details and shows only the essential features to the user.
It helps to reduce complexity and focus on what an object does, not how it does it.
Abstraction in C# can be achieved using:
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Abstract Classes
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Interfaces
🔹 1. Abstract Classes
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Cannot be instantiated directly
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Can contain abstract methods (no body) and concrete methods (with body)
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Derived classes must implement abstract methods
Example
🔹 2. Interfaces
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Defines a contract: methods/properties without implementation
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A class implements an interface and provides the implementation
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Supports multiple inheritance
Example
🔹 Abstract Class vs Interface
| Feature | Abstract Class | Interface |
|---|---|---|
| Instantiation | Cannot instantiate | Cannot instantiate |
| Methods | Abstract + Concrete | Only abstract (C# 8+ supports default implementations) |
| Fields | Allowed | Not allowed |
| Inheritance | Single | Multiple |
| Access Modifiers | Allowed | Public only (by default) |
🔹 Advantages of Abstraction
✔ Reduces complexity
✔ Focus on what an object does, not how
✔ Enforces a contract for derived classes
✔ Helps in scalable and maintainable design
🔹 Common Mistakes
❌ Trying to instantiate an abstract class
❌ Not implementing all interface methods
❌ Using abstract methods without override in derived class
🔹 Summary
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Abstraction hides implementation details
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Achieved using abstract classes or interfaces
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Forces derived classes to implement essential functionality
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Simplifies code and improves design
