TypeScript Study Plan

Your brief

For each unit, predict an example’s result, run the strict compiler, execute the supported fixture and make one deliberate change. Write a rejected input or invalid call as well as a successful one. Before advanced type operators, make sure you can explain unions and narrowing without assertions. Before Node or React integration, identify which runtime supplies the imported APIs and which package supplies declarations.

Run the code

Try in playground loads this source without running it. Choose Run when ready. The existing TypeScript 5.8.3 worker transpiles and executes one file; it does not perform full semantic type checking, load npm imports or provide DOM/Node APIs. Use the local compiler for the type contract.

For a full check, save the three downloads together in a new folder, run npm install, then npm run check. Use npm run build followed by npm start to execute the checked JavaScript with Node. The supplied project enables strict checking, indexed-access checks and exact optional properties.

• lesson.ts
• tsconfig.json
• package.json

Example

const stages = ["Values and functions", "Records and validation", "Generics and classes", "Modules and project tests"] as const;
stages.forEach((stage, index) => console.log((index + 1) + ". " + stage));

1. Values and functions
2. Records and validation
3. Generics and classes
4. Modules and project tests