Lesson 13 of 2357%
(Progress persistence is disabled until Phase 9)
TypeScript
Advanced
25 min
Intersection Types
Combine multiple types.
Learning Objectives
- The & operator
Intersection Types
Welcome to this lesson on Intersection Types. TypeScript builds on JavaScript by adding static typing, and mastering intersection types will help you build highly robust applications.
Explanation
TypeScript code is transformed into JavaScript via a compiler (or transpiler) before it runs in the browser. The types you write exist strictly at development time to help you catch errors early.
Code Examples
Here is how you might write this in TypeScript:
type Employee = { name: string };
type AdminEmployee = Admin & Employee;\n```
### Practical Example
To truly master this, try defining types for the data structures you use every day. It will instantly highlight edge cases you may have missed.
<Callout type="note">
**Note:** The BrowserCode Playground does not yet support native TypeScript execution. This feature is coming in a future phase!
</Callout>
### Try It Yourself
You can open the playground to see the code, but note that execution is currently restricted.
<TryItButton />
### Key Takeaways
- TypeScript catches errors before they happen.
- Types are erased when compiled to JavaScript.