Generic interface declaration in Typescript - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a generic interface named Container with a type parameter T.

Typescript

interface Container<[1]> {
  value: T;
}

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AT

BU

CV

DK

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase letters for generic type parameters.

Forgetting the angle brackets <> around the generic parameter.

The generic type parameter is usually named T by convention. It allows the interface to work with any type.

2fill in blank

medium

Complete the code to declare a generic interface Pair with two type parameters T and U.

Typescript

interface Pair<[1], U> {
  first: T;
  second: U;
}

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AV

BS

CK

DT

Attempts:

3 left

💡 Hint

Common Mistakes

Using a type parameter that is not referenced in the interface.

Swapping the order of type parameters.

The first generic type parameter is T, which is used for the first property.

3fill in blank

hard

Fix the error in the generic interface declaration by completing the code.

Typescript

interface Result<[1]> {
  data: T[];
  error?: string;
}

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AT

BU

CV

DE

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different letter for the generic parameter than the one used inside the interface.

Omitting the generic parameter entirely.

The generic type parameter T must match the type used inside the interface.

4fill in blank

hard

Fill both blanks to declare a generic interface Dictionary with key type K and value type V.

Typescript

interface Dictionary<[1], [2]> {
  [key: K]: V;
}

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AK

BT

CV

DU

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping the order of K and V.

Using type parameters not referenced in the interface.

The key type parameter is K and the value type parameter is V.

5fill in blank

hard

Fill all three blanks to declare a generic interface Triple with types A, B, and C for its properties.

Typescript

interface Triple<[1], [2], [3]> {
  first: A;
  second: B;
  third: C;
}

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

AA

BB

CC

DT

Attempts:

3 left

💡 Hint

Common Mistakes

Using the same letter for multiple generic parameters.

Not matching the generic parameters with the property types.

The generic parameters correspond to the property types: A, B, and C.