Why Records in C# Are Great (and So Nice to Work With)

Question

Why Records in C# Are Great

If you’ve been working with C# lately, you’ve probably encountered records , a feature introduced in C# 9 that many developers have come to love.

They’re elegant, powerful, and remove a lot of boilerplate when modeling data.

But what actually makes them great? Here’s why records aren’t just nice , they’re game-changing.

What Are Records?

At their core, records are reference types designed for immutable data modeling. Think of them as classes optimized for holding data with extra features built in.

You can define a record in two main ways:

✅ 1. Positional Syntax (Concise and Clean)

public record Person(string FirstName, string LastName);

This one-liner gives you:

• Constructor

• Equals(), GetHashCode(), and ToString() overrides

• init-only properties (immutable)

• Deconstruction support

Ouaaa...

In order to implement all that in a regular class, you'd need to write a lot of code constructors, equality logic, ToString() overrides, and possibly even a deconstructor.
Records do it all for you, automatically and cleanly.

✅ 2. Classic Syntax (More Flexible)

public record Person
{
    public string FirstName { get; init; }
    public string LastName { get; init; }
}

Need mutability? You can use set instead of init, but that sacrifices immutability and thread safety.

What is init?

init is a special accessor introduced in C# 9 that allows properties to be set only during initialization making them immutable afterward.

var person = new Person { FirstName = "Alice", LastName = "Green" };
// person.FirstName = "Bob"; ❌ Not allowed

✅ Cleaner than readonly fields
✅ Safer than public setters
✅ Perfect for records, DTOs, and configuration objects

Reference:
Microsoft Docs – Init-only Setters

✅ 1. Value-Based Equality — Finally Done Right

With classes, equality checks compare references. With records, it's based on content:

var a = new Person("Alice", "Smith");
var b = new Person("Alice", "Smith");

Console.WriteLine(a == b); // True ✅

Reference:
Microsoft Docs – Records

✅ 2. Immutability by Default — and Thread-Safe by Nature

Records are immutable by default, which leads to safer, more predictable code.

var p1 = new Person("John", "Doe");
var p2 = p1 with { FirstName = "Jane" }; // Creates a copy

And since their state can't be changed after creation, records are thread-safe for read operations — perfect for:

• Parallel tasks

• Background services

• Blazor state containers

• Event sourcing

Reference:
Immutability in C#

✅ 3. Concise and Readable Code
Records eliminate boilerplate. You define what matters — and the compiler handles the rest.

public record Invoice(string Id, DateTime Date, decimal Amount);

Clean. Lightweight. Clear.

✅ 4. Deconstruction and Pattern Matching

Records play perfectly with modern C# features:

var (first, last) = new Person("Ana", "Lopez");

if (p1 is { FirstName: "John" })
{
    Console.WriteLine("Hello John!");
}

Reference:

Pattern Matching in C#

✅ 5. Functional Programming Friendly

Records align with functional principles:

• No side effects

• Easy transformations

• Clear data flow

  var updatedInvoice = invoice with { Amount = invoice.Amount + 10 };

Reference:

Welcome to C# 9 – Records

✅ 6. Supports Inheritance, Structs, and More

You’re not locked into one pattern:

• record struct — value-type records

• readonly record struct — fully immutable

• Abstract and sealed record inheritance supported

Reference:
What's New in C# 10 – Record Structs

Records and the Value Object Pattern
In Domain-Driven Design (DDD), Value Objects are small objects that:

Represent a concept (e.g., Money, Email)

• Are immutable

• Have no identity

• Compare by value

✅ Records Are Ideal for Value Objects

public record Email(string Address)
{
    public Email
    {
        if (!Address.Contains("@"))
            throw new ArgumentException("Invalid email");
    }
}

You get a clean, reusable object with built-in validation and equality , no fuss.

public record Money(decimal Amount, string Currency);

public record Product
{
    public Guid Id { get; init; }
    public string Name { get; init; }
    public Money Price { get; init; }
}

Reference:
Martin Fowler – Value Object

When Not to Use Records

Avoid records if:

• You need full mutable entities (e.g., for EF Core)

• You rely on reference identity

• Your inheritance hierarchy is too complex

Real-World Use Cases

✅ DTOs for APIs

✅ Immutable configs

✅ Logging and audit trails

✅ Domain Value Objects

✅ State models in Blazor, Redux, Fluxor

✅ Event-driven architecture

Final Thoughts
C# records are more than just syntactic sugar — they promote a mindset of immutability, clarity, and value-based design.

They:

• Reduce bugs

• Simplify data models

• Improve thread safety

• Save a lot of time

Whether you're building APIs, desktop apps, or microservices, records make your C# experience cleaner and smarter.

Once you go record, you'll never want to class again.

References:

Microsoft Docs – Records

Init-only Setters in C# 9

Immutability

Pattern Matching

Dev Blog – Welcome to C# 9

Martin Fowler – Value Objects

Comments

Great breakdown of why records are such a game-changer in C#, really appreciate how you explained it! Curious though, have you found any gotchas or performance hits when using records heavily in large-scale apps? Nice one....

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Thanks for your insights , really appreciate the breakdown!
Records should be performant since they’re essentially classes under the hood, but optimized for immutability and value-based equality.