JavaScript & TypeScript

How it is taught

1. Step 1

   Start where you are

   A short placement task, graded by the tutor, starts you past the modules you can already do.

2. Step 2

   Learn in conversation

   Each concept is one session: the tutor explains, asks you to write code, and reviews it until you have shown you understand.

3. Step 3

   Keep it

   Every concept comes back on day 3, 7 and 18. A memory model tracks how well each one is holding, and reviews can go straight into your Google Calendar.

What you will learn

Each concept has its own page: what a session covers, an example and the mistake to watch for.

1. Module 1Types, values and inference

   • Primitive types
   • Type inference
   • Type annotations

2. Module 2Functions and overloads

   • Function types
   • Optional and default parameters
   • Overload signatures

3. Module 3Objects, interfaces, unions

   • Interfaces and type aliases
   • Union types
   • Literal types

4. Module 4Narrowing and control flow

   • typeof and in guards
   • Discriminated unions
   • Exhaustiveness checks

5. Module 5Generics in practice

   • Type parameters
   • keyof constraints
   • Generic defaults and inference

6. Module 6Async patterns and fetch

   • Promises and async/await
   • Promise.all and rejection
   • Typed fetch responses

7. Module 8Modules and tooling

   • ES modules
   • tsconfig essentials
   • Declaration files

8. Module 9Classes and composition

   • Class fields and access modifiers
   • Implementing interfaces
   • Composition over inheritance

9. Module 10Utility and mapped types

   • Partial, Pick and Omit
   • Mapped types
   • Conditional types

10. Module 11Errors and validation

    • Error handling patterns
    • The unknown type
    • Runtime validation