Lesson 35 of 55
15 mins readAbstract Classes and Methods
In Plain English
Abstract classes serve as base classes from which other classes may be derived. Unlike interfaces, abstract classes can contain implementation details for their members.
Core Rules to Remember
Template Methods: Combines abstract method contracts with shared concrete implementations.
No Direct Instantiation: Abstract classes cannot be instantiated with new directly.
Live Interactive Example
Hit Run Code to see it liveTemplate Pattern with Abstract Classes
Python 3.12
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Output Console
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How it works: PaymentProcessor cannot be instantiated directly; StripeProcessor provides the required processPayment implementation.
Your Turn: Micro Challenge
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Micro Exercise
Build Abstract Database Driver
- Declare abstract class Database with constructor(public connectionString: string).
- Add abstract connect(): boolean and concrete describe(): string returning `DB at ${this.connectionString}`.
- Create class MongoDb extending Database with connect() returning true. Print describe() and connect().
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Sandbox Output
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