Day 4 of 14 30 minObject typesinterfaceOptional & readonly
Describe the shape of your data. Write object types and interfaces with optional and readonly properties, extend interfaces, type dictionaries with index signatures, and learn when to use interface versus type.
By the end of today you can
- Describe object shapes with interfaces and type aliases
- Use optional and readonly properties
- Extend interfaces and combine types with intersections
- Type dictionary-like objects with index signatures and Record
- Explain structural typing and excess property checks
What's inside
- 5 sections
- 2 diagrams and mind maps
- 6 code examples you can run
- 5-question quiz
- 1Interfaces
- 2type aliases do the same job
- 3Extending and combining
- 4Dictionaries: index signatures and Record
- 5Structural typing
Sign in free to read this lesson
Get the full lesson with diagrams, runnable code and the quiz. Your progress is saved across devices.
Sign in free