Practice Exercises - Set 1 (Basics)

Let's think about this for a second

This lesson gives you practice tasks to directly write out your own code applying what you know about basic types, functions, and interfaces from the tutorial's Basic chapter. Rather than teaching new concepts, the goal is to cement the syntax you've learned in earlier lessons into memory. For each task, open a TypeScript file yourself and write it out, and if a compiler error pops up, read the error message carefully and think through why it happened. Practicing type annotations with your own hands is the best way to learn.

Exercises

Task 1: Write a function celsiusToFahrenheit(celsius: number): number implementing the formula (celsius * 9/5) + 32. Task 2: Create an interface Book with the fields title: string, author: string, year: number, isAvailable: boolean, and create an array containing three Book objects. Task 3: Write a function getAvailableBooks(books: Book[]): string[] that combines filter() and map() to return, as an array, just the titles of the books where isAvailable is true.

• Did you write celsiusToFahrenheit() with the correct return type?
• Did you correctly define the Book interface with all four fields?
• Does getAvailableBooks() correctly chain filter() and map()?

Sample code

// Task 1
function celsiusToFahrenheit(celsius: number): number {
  // TODO: implement
  return 0;
}

// Task 2
interface Book {
  title: string;
  author: string;
  year: number;
  isAvailable: boolean;
}

const books: Book[] = [
  // TODO: add 3 book objects
];

// Task 3
function getAvailableBooks(books: Book[]): string[] {
  // TODO: implement using filter() + map()
  return [];
}

console.log(celsiusToFahrenheit(100));
console.log(getAvailableBooks(books));

celsiusToFahrenheit(100) returns 212, and getAvailableBooks(books) returns an array of the titles of books where isAvailable is true.