Removing modifiers with minus in Typescript - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to remove the 'readonly' modifier from the type.

Typescript

type Mutable<T> = [1] T;

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

Areadonly

B+readonly

C-readonly

Dreadonly-

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'readonly' instead of '-readonly' which adds the modifier instead of removing it.

Using '+readonly' which adds the modifier.

Placing the minus sign after 'readonly' which is invalid syntax.

Using -readonly removes the readonly modifier from the type properties.

2fill in blank

medium

Complete the code to remove the 'optional' modifier from all properties of type T.

Typescript

type RequiredProps<T> = { [P in keyof T]-[1]: T[P] };

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

A+?

B-?

C?

Attempts:

3 left

💡 Hint

Common Mistakes

Using '+?' which adds the optional modifier.

Using '?' alone which does not remove the modifier.

Using duplicate '?' which is invalid.

The -? modifier removes the optional property modifier from each property.

3fill in blank

hard

Fix the error in the code to correctly remove the 'readonly' modifier from type T.

Typescript

type Writable<T> = { -[1] P in keyof T: T[P] };

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

Areadonly

Breadonly-

Creadonly?

Dreadonly+

Attempts:

3 left

💡 Hint

Common Mistakes

Placing the minus sign after 'readonly' which is invalid.

Adding '+' instead of '-' which adds the modifier.

Using 'readonly?' which is not valid here.

The correct syntax is -readonly before the property name to remove the readonly modifier.

4fill in blank

hard

Fill both blanks to create a type that removes both 'readonly' and 'optional' modifiers from T.

Typescript

type FullyMutable<T> = { -[1] P in keyof T-[2]: T[P] };

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

Areadonly

B?

Dreadonly?

Attempts:

3 left

💡 Hint

Common Mistakes

Leaving the second blank empty which does not remove optional.

Using '+readonly' which adds readonly instead of removing.

Using 'readonly?' which is invalid syntax.

Use -readonly to remove readonly and -? to remove optional modifiers.

5fill in blank

hard

Fill all three blanks to create a type that removes 'readonly' and 'optional' modifiers and converts keys to uppercase strings.

Typescript

type UppercaseMutable<T> = { -[1] [2] in keyof T as [3]: T[[2]] };

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

Areadonly

BP

CUppercase<string & P>

DK

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'K' instead of 'P' as the key variable.

Not removing readonly modifier.

Not transforming keys to uppercase.

Remove readonly with -readonly, use P as the key variable, and convert keys to uppercase with Uppercase<string & P>.