With expressions for immutable copies in C Sharp (C#) - Mini Project: Build & Apply

Using With Expressions for Immutable Copies in C#

📖 Scenario: You are managing a list of books in a library system. Each book has a title, author, and year published. You want to create a new version of a book with some changes, but keep the original book unchanged.

🎯 Goal: Learn how to use with expressions to create immutable copies of records with updated properties in C#.

📋 What You'll Learn

Create a record type called Book with properties Title, Author, and Year.

Create an instance of Book with specific values.

Create a new Book instance using a with expression to change one property.

Print the original and the new Book instances to show they are different.

💡 Why This Matters

🌍 Real World

Immutable data helps avoid bugs by preventing accidental changes. With expressions let you easily create modified copies of data.

💼 Career

Understanding immutable data and with expressions is useful for writing safe, clear, and maintainable C# code in professional software development.

1

Create the Book record

Create a record called Book with three properties: string Title, string Author, and int Year.

C Sharp (C#)

// Your code here

Need a hint?

Use the record keyword to create an immutable data type with properties.

2

Create an instance of Book

Create a variable called originalBook and assign it a new Book with Title set to "The Hobbit", Author set to "J.R.R. Tolkien", and Year set to 1937.

C Sharp (C#)

public record Book(string Title, string Author, int Year);
// Your code here

Need a hint?

Create a new Book object by calling its constructor with the given values.

3

Create a modified copy with a with expression

Create a variable called updatedBook that is a copy of originalBook but with the Year changed to 1951 using a with expression.

C Sharp (C#)

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

Book originalBook = new Book("The Hobbit", "J.R.R. Tolkien", 1937);
// Your code here

Need a hint?

Use the with keyword followed by braces to change the Year property while copying.

4

Print both books to compare

Write two Console.WriteLine statements to print originalBook and updatedBook so you can see the difference.

C Sharp (C#)

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

Book originalBook = new Book("The Hobbit", "J.R.R. Tolkien", 1937);

Book updatedBook = originalBook with { Year = 1951 };
// Your code here

Need a hint?

Use Console.WriteLine to print each book variable.