Why object types are needed in Typescript - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare an object type for a person with a name and age.

Typescript

type Person = { name: string; age: [1] };

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Aboolean

Bnumber

Cstring

Dany

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'string' for age instead of 'number'.

Using 'boolean' which is true/false, not suitable here.

The age property should be a number because age is a numeric value.

2fill in blank

medium

Complete the code to create a variable with the Person type.

Typescript

const user: [1] = { name: 'Alice', age: 30 };

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APerson

Bobject

Cstring

Dany

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'string' or 'object' instead of the custom type 'Person'.

Using 'any' which disables type checking.

The variable user should be typed as Person to match the object structure.

3fill in blank

hard

Fix the error in the function parameter type to accept a Person object.

Typescript

function greet(person: [1]) { console.log(`Hello, ${person.name}`); }

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Astring

Bany

Cnumber

DPerson

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'string' which causes an error accessing 'name'.

Using 'number' or 'any' which are not specific types.

The function expects a Person type to access name property safely.

4fill in blank

hard

Fill both blanks to create a function that returns the person's age.

Typescript

function getAge([1]: Person): [2] { return [1].age; }

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Aperson

Bnumber

Cstring

Dage

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'string' as return type instead of 'number'.

Using 'age' as parameter name without type.

The function takes a parameter named person of type Person and returns a number representing the age.

5fill in blank

hard

Fill all three blanks to create a typed object and access its properties.

Typescript

type [1] = { [2]: string; [3]: number };

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

APerson

Bname

Cage

DUser

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'User' instead of 'Person' as type name.

Mixing up property names or types.

The type is named Person with properties name (string) and age (number).