Sorting Stability and When to Use Which Sort in DSA Javascript - Build from Scratch

Sorting Stability and When to Use Which Sort

📖 Scenario: You work at a bookstore that keeps a list of books with their titles and prices. Sometimes, books have the same price. You want to sort the books by price but keep the order of books with the same price as they were originally. This is called a stable sort.Later, you want to understand when to use different sorting methods based on speed and stability.

🎯 Goal: You will create a list of books, add a sorting preference, sort the books by price using a stable sort, and then print the sorted list showing how stable sorting keeps the original order for books with the same price.

📋 What You'll Learn

Create an array of book objects with exact titles and prices

Add a variable to choose sorting method

Use a stable sorting method to sort books by price

Print the sorted list showing title and price

💡 Why This Matters

🌍 Real World

Sorting lists of products, books, or any items by price or other attributes is common in online stores and inventory systems. Stable sorting helps keep the original order when items have the same key, which can be important for user experience.

💼 Career

Understanding sorting stability and when to use stable or unstable sorts is important for software developers working on data processing, UI lists, and performance optimization.

1

Create the list of books

Create an array called books with these exact objects in this order: { title: 'Book A', price: 30 }, { title: 'Book B', price: 20 }, { title: 'Book C', price: 30 }, { title: 'Book D', price: 10 }

DSA Javascript

// Create the array books with the given book objects
// Your code here

Hint

Use const books = [ ... ] with objects inside curly braces.

2

Add sorting method choice

Create a variable called useStableSort and set it to true to choose stable sorting

DSA Javascript

const books = [
  { title: 'Book A', price: 30 },
  { title: 'Book B', price: 20 },
  { title: 'Book C', price: 30 },
  { title: 'Book D', price: 10 }
];

// Create useStableSort and set it to true
// Your code here

Hint

Use const useStableSort = true; to set the sorting method.

3

Sort the books by price using stable sort

Use books.sort() with a compare function that compares a.price and b.price to sort the books by price in ascending order. Use the variable useStableSort to decide if sorting should happen.

DSA Javascript

const books = [
  { title: 'Book A', price: 30 },
  { title: 'Book B', price: 20 },
  { title: 'Book C', price: 30 },
  { title: 'Book D', price: 10 }
];

const useStableSort = true;

// Sort books by price using books.sort() and useStableSort
// Your code here

Hint

Use books.sort((a, b) => a.price - b.price) to sort by price ascending.

4

Print the sorted list of books

Use a for loop with variables book to go through books and print each book's title and price in the format Title: Book A, Price: 30

DSA Javascript

const books = [
  { title: 'Book A', price: 30 },
  { title: 'Book B', price: 20 },
  { title: 'Book C', price: 30 },
  { title: 'Book D', price: 10 }
];

const useStableSort = true;

if (useStableSort) {
  books.sort((a, b) => a.price - b.price);
}

// Print each book's title and price
// Your code here

Hint

Use for (const book of books) and console.log with template strings.