Generic array syntax in Typescript - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare an array of numbers using generic syntax.

Typescript

let numbers: Array<[1]> = [1, 2, 3];

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Astring

Bboolean

Cany

Dnumber

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'string' or 'boolean' instead of 'number' for the array type.

The generic array syntax uses Array<Type>. Here, number specifies the array holds numbers.

2fill in blank

medium

Complete the code to declare an array of strings using generic syntax.

Typescript

const fruits: Array<[1]> = ['apple', 'banana', 'cherry'];

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Astring

Bobject

Cboolean

Dnumber

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'number' or 'object' instead of 'string' for the array type.

The array holds strings, so the generic type should be string.

3fill in blank

hard

Fix the error in the generic array declaration.

Typescript

let flags: Array[1] = [true, false, true];

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A[boolean]

B<boolean>

C(boolean)

D{boolean}

Attempts:

3 left

💡 Hint

Common Mistakes

Using square brackets or parentheses instead of angle brackets.

The correct generic syntax uses angle brackets: Array<boolean>.

4fill in blank

hard

Fill both blanks to declare an array of objects with a generic type.

Typescript

const users: Array<[1]> = [[2]];

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A{ name: string; age: number }

B{ name: 'Alice', age: 30 }

C{ name: 'Bob', age: 25 }

Dstring

Attempts:

3 left

💡 Hint

Common Mistakes

Using a string type instead of an object type for the generic.

Putting the object type inside the array instead of an object instance.

The generic type defines the shape of objects in the array. The array contains objects matching that shape.

5fill in blank

hard

Fill all three blanks to declare and initialize a generic array of booleans.

Typescript

let flags: Array<[1]> = [[2], [3]];

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

Aboolean

Btrue

Cfalse

Dstring

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'string' as the generic type.

Using non-boolean values inside the array.

The generic type is boolean. The array contains boolean values true and false.