Constructor parameter types in Typescript - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a constructor parameter type for name.

Typescript

class Person {
  name: string;
  constructor(name: [1]) {
    this.name = name;
  }
}

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

Astring

Bnumber

Cboolean

Dany

Attempts:

3 left

💡 Hint

Common Mistakes

Using number or boolean instead of string for the name parameter.

The constructor parameter name should be of type string to match the property type.

2fill in blank

medium

Complete the code to declare a constructor parameter type for age.

Typescript

class User {
  age: [1];
  constructor(age: number) {
    this.age = age;
  }
}

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

Astring

Bany

Cnumber

Dboolean

Attempts:

3 left

💡 Hint

Common Mistakes

Using string type for age instead of number.

The age property and constructor parameter should both be number type.

3fill in blank

hard

Fix the error in the constructor parameter type for isActive.

Typescript

class Account {
  isActive: boolean;
  constructor(isActive: [1]) {
    this.isActive = isActive;
  }
}

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

Aboolean

Bnumber

Cstring

Dany

Attempts:

3 left

💡 Hint

Common Mistakes

Using string or number type for boolean properties.

The isActive property is a boolean, so the constructor parameter must also be boolean.

4fill in blank

hard

Fill both blanks to declare constructor parameter types for title and pages.

Typescript

class Book {
  title: [1];
  pages: [2];
  constructor(title: string, pages: number) {
    this.title = title;
    this.pages = pages;
  }
}

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

Astring

Bnumber

Cboolean

Dany

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up types between title and pages.

The title is text, so it uses string. The pages is a number, so it uses number.

5fill in blank

hard

Fill all three blanks to declare constructor parameter types for username, email, and verified.

Typescript

class Member {
  username: [1];
  email: [2];
  verified: [3];
  constructor(username: string, email: string, verified: boolean) {
    this.username = username;
    this.email = email;
    this.verified = verified;
  }
}

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

Astring

Bboolean

Cnumber

Dany

Attempts:

3 left

💡 Hint

Common Mistakes

Using number type for username or email.

Using string type for verified flag.

username and email are text, so they use string. verified is a true/false flag, so it uses boolean.