Nested object types in Typescript - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a nested object type with a property 'address'.

Typescript

type User = {
  name: string;
  address: [1];
};

Drag options to blanks, or click blank then click option'

A{ street: string; city: string }

Bnumber

Cstring

Dboolean

Attempts:

3 left

💡 Hint

Common Mistakes

Using a simple type like string instead of an object type for address.

The property address is an object with nested properties street and city, so it needs an object type.

2fill in blank

medium

Complete the code to access the nested property 'city' from the user object.

Typescript

const user: User = {
  name: 'Alice',
  address: { street: 'Main St', city: 'Wonderland' }
};

const cityName = user.address.[1];

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Acity

Baddress

Cname

Dstreet

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to access a property that doesn't exist at that level.

Using the wrong property name.

To get the city name, access the city property inside the address object.

3fill in blank

hard

Fix the error in the nested object type by completing the type for 'company'.

Typescript

type Employee = {
  id: number;
  company: [1];
};

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Astring

B{ name: string; location: string }

Cnumber

Dboolean

Attempts:

3 left

💡 Hint

Common Mistakes

Using a primitive type like string instead of an object type for company.

The company property is an object with name and location properties, so it needs an object type.

4fill in blank

hard

Fill both blanks to define a nested object type with an array of objects.

Typescript

type Book = {
  title: string;
  author: [1];
};

type Library = {
  name: string;
  books: [2][];
};

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ABook

Bstring

Cnumber

Dboolean

Attempts:

3 left

💡 Hint

Common Mistakes

Using a primitive type for books instead of an array of objects.

Using wrong type for author.

The books property is an array of Book objects, and the author property inside Book is a string.

5fill in blank

hard

Fill all three blanks to define a nested object type with optional and nested properties.

Typescript

type Profile = {
  username: string;
  contact: {
    email: [1];
    phone?: [2];
  };
  preferences: [3];
};

Drag options to blanks, or click blank then click option'

Astring

Bnumber

C{ theme: string; notifications: boolean }

Dboolean

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong types for email or phone.

Not defining preferences as an object.

The email is a string, phone is an optional number, and preferences is an object with theme and notifications properties.