Why utility types are needed in Typescript - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a type that makes all properties optional.

Typescript

type PartialUser = [1]<User>;

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

ARequired

BReadonly

CPartial

DPick

Attempts:

3 left

💡 Hint

Common Mistakes

Using Required instead of Partial, which makes all properties required.

Using Readonly which makes properties immutable, not optional.

The Partial utility type makes all properties of a type optional.

2fill in blank

medium

Complete the code to create a type that makes all properties required.

Typescript

type CompleteUser = [1]<User>;

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

APartial

BPick

CReadonly

DRequired

Attempts:

3 left

💡 Hint

Common Mistakes

Using Partial which makes properties optional instead of required.

Using Readonly which only changes mutability.

The Required utility type makes all properties of a type required.

3fill in blank

hard

Fix the error in the code to create a type with only the 'name' property from User.

Typescript

type UserName = [1]<User, 'name'>;

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

ARequired

BPick

CPartial

DOmit

Attempts:

3 left

💡 Hint

Common Mistakes

Using Omit which excludes properties instead of selecting.

Using Partial or Required which change optionality, not selection.

The Pick utility type selects specific properties from a type.

4fill in blank

hard

Fill both blanks to create a type that excludes 'password' and makes remaining properties readonly.

Typescript

type SafeUser = [1]<[2]<User, 'password'>>;

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

AReadonly

BPartial

COmit

DPick

Attempts:

3 left

💡 Hint

Common Mistakes

Reversing the order of utility types.

Using Pick instead of Omit which selects properties instead of excluding.

First, Omit removes the 'password' property, then Readonly makes the rest immutable.

5fill in blank

hard

Fill all three blanks to create a type that makes 'email' optional, picks 'name' and 'email', and makes them readonly.

Typescript

type CustomUser = [1]<[2]<User, 'name' | 'email'>> & { email?: [3] };

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

AReadonly

BPick

Cstring

DPartial

Attempts:

3 left

💡 Hint

Common Mistakes

Using Partial instead of Pick for selection.

Not overriding 'email' to be optional.

We pick 'name' and 'email', make them readonly, and then override 'email' to be optional with type string.