TypeScript Utility Types

Partial, Required, Pick, Omit, Record and Readonly.

✍️ 3 exercises + code challenge in this lesson

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TypeScript has built-in helpers that transform types:

Partial<T>: all properties optional.
Required<T>: all properties required.
Pick<T, "a" | "b"> / Omit<T, "a">: keep or remove properties.
Record<K, V>: an object with keys K and values V.
Readonly<T>: nothing can be changed.

Key Takeaways: TypeScript Utility Types

Mastering TypeScript Utility Types helps you write clean and reliable TypeScript code. Follow standard conventions, test edge cases, and keep logic simple. Try running the code example below and complete the exercises to build confidence.

TypeScript Utility Types Code Example

TypeScript

interface User {
  id: number;
  name: string;
  email: string;
}

const update: Partial<User> = { name: "New name" };
const preview: Pick<User, "id" | "name"> = { id: 1, name: "Ali" };
const scores: Record<string, number> = { ali: 80, sara: 92 };

console.log(Object.keys(update).length, preview.name, scores.sara);

Output

1 Ali 92

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TypeScript Utility Types Practice Exercises

Check what you learned in “TypeScript Utility Types”.

/ 3 solved

Fill in the blank

Make all properties optional.

const patch: <User> = { name: "New" };

✓ Correct! Not quite. Try again.

Multiple choice

Which utility type removes properties from a type?

Omit Pick Partial Record

✓ Correct! Not quite. Try again.

Code challenge

Create const prices: Record<string, number> = { tea: 50, coffee: 120 } and log prices.coffee.

Write the code in the live editor. Your answer is checked automatically.

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to save your exercise progress.

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TypeScript Generics

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TypeScript Narrowing & Type Guards

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TypeScript Utility Types

💡 Key Takeaways: TypeScript Utility Types

TypeScript Utility Types Code Example

TypeScript Utility Types Practice Exercises

Key Takeaways: TypeScript Utility Types