Why advanced LINQ matters in C Sharp (C#) - See It in Action

Why advanced LINQ matters

📖 Scenario: Imagine you work in a company that manages a large list of books in a library. You need to find books based on different conditions quickly and clearly. Using advanced LINQ helps you write simple and readable code to get exactly what you want from big data collections.

🎯 Goal: You will build a small C# program that uses advanced LINQ queries to filter and select books from a list based on specific conditions.

📋 What You'll Learn

Create a list of books with title, author, and year

Add a variable to set a year threshold

Use LINQ to find books published after the threshold year

Print the filtered list of book titles

💡 Why This Matters

🌍 Real World

Filtering and selecting data from collections is common in apps like libraries, stores, or social media feeds.

💼 Career

Knowing advanced LINQ helps developers write clean, efficient code to handle data queries in real projects.

1

Create the list of books

Create a list called books of type List<Book> with these exact entries: new Book("The Hobbit", "J.R.R. Tolkien", 1937), new Book("1984", "George Orwell", 1949), new Book("Clean Code", "Robert C. Martin", 2008).

C Sharp (C#)

public record Book(string Title, string Author, int Year);

using System.Collections.Generic;

// Create the list of books
// Your code here

Need a hint?

Use List<Book> and add the three books exactly as shown.

2

Add a year threshold

Create an integer variable called yearThreshold and set it to 1950.

C Sharp (C#)

public record Book(string Title, string Author, int Year);

using System.Collections.Generic;

List books = new List
{
    new Book("The Hobbit", "J.R.R. Tolkien", 1937),
    new Book("1984", "George Orwell", 1949),
    new Book("Clean Code", "Robert C. Martin", 2008)
};

// Create the year threshold
// Your code here

Need a hint?

Just create a simple integer variable with the exact name and value.

3

Use LINQ to filter books

Use LINQ with a var variable called recentBooks to select books from books where the Year is greater than yearThreshold. Use a LINQ query expression with from, where, and select.

C Sharp (C#)

public record Book(string Title, string Author, int Year);

using System.Collections.Generic;

List books = new List
{
    new Book("The Hobbit", "J.R.R. Tolkien", 1937),
    new Book("1984", "George Orwell", 1949),
    new Book("Clean Code", "Robert C. Martin", 2008)
};

int yearThreshold = 1950;

// Use LINQ query to find recent books
// Your code here

Need a hint?

Use a LINQ query expression with from, where, and select keywords exactly as shown.

4

Print the filtered book titles

Use a foreach loop with variable book to iterate over recentBooks and print each book's Title using Console.WriteLine.

C Sharp (C#)

public record Book(string Title, string Author, int Year);

using System.Collections.Generic;
using System.Linq;

List books = new List
{
    new Book("The Hobbit", "J.R.R. Tolkien", 1937),
    new Book("1984", "George Orwell", 1949),
    new Book("Clean Code", "Robert C. Martin", 2008)
};

int yearThreshold = 1950;

var recentBooks = from book in books
                  where book.Year > yearThreshold
                  select book;

// Print the titles of recent books
// Your code here

Need a hint?

Use a foreach loop and Console.WriteLine(book.Title) to print each title.