Type alias vs inline types in Typescript - Hands-On Comparison

Type alias vs inline types

📖 Scenario: You are building a simple TypeScript program to manage information about books in a library.Each book has a title (string), author (string), and year (number).

🎯 Goal: You will first create a type alias for the book type, then create a list of books using that alias. Next, you will create another list of books using inline types directly. Finally, you will print the titles of all books from both lists.

📋 What You'll Learn

Create a type alias called Book with title, author, and year properties

Create a variable libraryBooks as an array of Book using the type alias

Create a variable newBooks as an array using inline types (no alias)

Print the titles of all books from both libraryBooks and newBooks

💡 Why This Matters

🌍 Real World

Type aliases help developers define clear and reusable data shapes, making code easier to read and maintain in real projects like library management or inventory systems.

💼 Career

Understanding type aliases and inline types is essential for TypeScript developers to write clean, scalable code and collaborate effectively in teams.

1

Create a type alias for books

Create a type alias called Book with properties: title (string), author (string), and year (number).

Typescript

# Your code here

Need a hint?

Use the type keyword to create a type alias with the specified properties.

2

Create a list of books using the type alias

Create a variable called libraryBooks as an array of Book with these exact entries:
{ title: "1984", author: "George Orwell", year: 1949 },
{ title: "To Kill a Mockingbird", author: "Harper Lee", year: 1960 }.

Typescript

type Book = {
  title: string;
  author: string;
  year: number;
};
# Your code here

Need a hint?

Use const libraryBooks: Book[] = [...] to create the array with the given objects.

3

Create a list of books using inline types

Create a variable called newBooks as an array with inline types (no alias) with these exact entries:
{ title: "The Great Gatsby", author: "F. Scott Fitzgerald", year: 1925 },
{ title: "Brave New World", author: "Aldous Huxley", year: 1932 }.

Typescript

type Book = {
  title: string;
  author: string;
  year: number;
};

const libraryBooks: Book[] = [
  { title: "1984", author: "George Orwell", year: 1949 },
  { title: "To Kill a Mockingbird", author: "Harper Lee", year: 1960 }
];
# Your code here

Need a hint?

Use inline type syntax inside the array type annotation for newBooks.

4

Print all book titles from both lists

Write code to print the titles of all books from libraryBooks and newBooks. Use a for loop with variable book to iterate over each array and print book.title.

Typescript

type Book = {
  title: string;
  author: string;
  year: number;
};

const libraryBooks: Book[] = [
  { title: "1984", author: "George Orwell", year: 1949 },
  { title: "To Kill a Mockingbird", author: "Harper Lee", year: 1960 }
];

const newBooks: { title: string; author: string; year: number }[] = [
  { title: "The Great Gatsby", author: "F. Scott Fitzgerald", year: 1925 },
  { title: "Brave New World", author: "Aldous Huxley", year: 1932 }
];
# Your code here

Need a hint?

Use two for loops to print each book's title from both arrays.