Beginner LevelSoftware Engineering Principles
What is the Strategy Pattern and how does it encapsulate interchangeable algorithms?
❓ Interview Prompt: Explain the Strategy Behavioral Pattern, strategy interfaces, eliminating conditional `if/else` branching, and runtime algorithm swapping.
The Strategy Pattern defines a family of algorithms, encapsulates each one inside a separate class, and makes them interchangeable at runtime:
Benefits:
Replaces bloated, nested 'if-else' or 'switch' statements with clean polymorphic behavior, adhering to the Open/Closed Principle.
Code Implementation Example
typescript
interface PaymentStrategy { pay(amount: number): void; }
class CreditCardStrategy implements PaymentStrategy { pay(amt: number) { console.log('Paid \\${amt} via Credit Card'); } }
class PayPalStrategy implements PaymentStrategy { pay(amt: number) { console.log('Paid \\${amt} via PayPal'); } }
class ShoppingCart {
constructor(private strategy: PaymentStrategy) {}
checkout(amount: number) { this.strategy.pay(amount); }
}💡Swapping payment algorithms at runtime using the Strategy pattern.
🎯 Interview Key Takeaway
Encapsulate interchangeable algorithms inside Strategy classes to eliminate nested switch/if statements.
#Strategy#Design Patterns#Behavioral#Beginner
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