RivoCode

TypeScript in Depth · Final Project · Lesson 15 of 16

Planning a Typed App

Concept

Planning a Typed App

Sketch your interfaces first. Once your data shapes are defined, the rest of your code becomes much safer to write.

By the end of this lesson
  • Explain the core idea behind Planning a Typed App.
  • Predict output before running a change.
  • Test one realistic and one unusual input.
  • Use the result to make the next decision.
How to study this page
  1. 1. Read one concept.
  2. 2. Change the example.
  3. 3. Run, compare, and explain.
  4. 4. Complete the challenge below.
ExampleRunnable
interface Task {
  id: string;
  title: string;
  done: boolean;
}
Try it Yourself »
Self-check before continuing

Without looking at the example, describe what changes when you modify one input in Planning a Typed App. Then reopen the editor and prove your explanation with a small test.

You are ready to continue when you can predict, test, and explain the result.

Your turn

Define the interfaces you would need for a small typed todo app.

Loading editor…

Console

Output will appear here...