Why LINQ is needed in C Sharp (C#) - See It in Action

Why LINQ is needed

📖 Scenario: Imagine you have a list of books with their titles and prices. You want to find all books cheaper than a certain price. Doing this manually can be slow and messy.

🎯 Goal: You will create a simple list of books, set a price limit, use LINQ to find books cheaper than that limit, and print their titles.

📋 What You'll Learn

Create a list of books with exact titles and prices

Create a price limit variable

Use LINQ query syntax to select books cheaper than the price limit

Print the titles of the selected books

💡 Why This Matters

🌍 Real World

LINQ is used in real apps to quickly search, filter, and organize data like lists of products, users, or orders.

💼 Career

Knowing LINQ is important for C# developers because it simplifies data handling and makes code easier to read and maintain.

1

Create the list of books

Create a list called books containing these exact entries: ("C# Basics", 30), ("LINQ Guide", 25), ("Advanced C#", 40) as tuples with Title and Price.

C Sharp (C#)

// Create the list of books with Title and Price
// Your code here

Need a hint?

Use new List<(string Title, int Price)> { ... } to create the list.

2

Set the price limit

Create an integer variable called priceLimit and set it to 30.

C Sharp (C#)

var books = new List
{
    ("C# Basics", 30),
    ("LINQ Guide", 25),
    ("Advanced C#", 40)
};

// Create priceLimit variable
// Your code here

Need a hint?

Use int priceLimit = 30; to set the limit.

3

Use LINQ to find cheap books

Use a LINQ query with from, where, and select to create a variable called cheapBooks that contains books from books where Price is less than priceLimit.

C Sharp (C#)

var books = new List
{
    ("C# Basics", 30),
    ("LINQ Guide", 25),
    ("Advanced C#", 40)
};

int priceLimit = 30;

// Use LINQ query to find cheapBooks
// Your code here

Need a hint?

Use from book in books where book.Price < priceLimit select book;

4

Print the titles of cheap books

Use a foreach loop with variable book to print the Title of each book in cheapBooks using Console.WriteLine(book.Title);.

C Sharp (C#)

var books = new List
{
    ("C# Basics", 30),
    ("LINQ Guide", 25),
    ("Advanced C#", 40)
};

int priceLimit = 30;

var cheapBooks = from book in books
                 where book.Price < priceLimit
                 select book;

// Print titles of cheapBooks
// Your code here

Need a hint?

Use foreach (var book in cheapBooks) { Console.WriteLine(book.Title); }