🔍 Overview
Chapter 3 introduces the concept of composition in type systems—how smaller types can be combined to form more complex ones. Composition is a powerful tool for building scalable and reusable code.
💡 Key Concepts
- Object Types: Shows how to define structured types using key-value pairs.
- Nested Types: Explains how types can contain other types, enabling hierarchical modeling.
- Optional Properties: Introduces the `?` modifier to indicate that a property may be undefined.
- Readonly Properties: Demonstrates how to enforce immutability using `readonly`.
- Intersection Types: Combines multiple types into one using the `&` operator.
- Type Composition Patterns: Encourages building types from smaller, reusable components.
🧭 Takeaway
Composition allows developers to model complex data structures in a clean and maintainable way. By combining and nesting types, TypeScript becomes a powerful language for expressing real-world domain logic.