C# record vs class: equality, immutability and with expressions

updated 2026-10-21

tool: C#
compares: record vs class

A C# record is a class with value-based equality: two records are equal when all their properties are equal, while two class instances are equal only when they are the same object. Records declared with positional parameters (record Point(int X, int Y)) get init-only properties, a readable ToString(), deconstruction and non-destructive copies with with. Use records for data that is compared by value (DTOs, messages, keys); use classes for objects with identity and changing state.

Side by side

bash

export DOTNET_NOLOGO=1 DOTNET_CLI_TELEMETRY_OPTOUT=1
dotnet new console -o app >/dev/null 2>&1
cd app
cat > Program.cs <<'EOF'
var r1 = new PointRecord(1, 2);
var r2 = new PointRecord(1, 2);
var c1 = new PointClass { X = 1, Y = 2 };
var c2 = new PointClass { X = 1, Y = 2 };

Console.WriteLine($"record equal: {r1 == r2}, Equals: {r1.Equals(r2)}");
Console.WriteLine($"class  equal: {c1 == c2}, Equals: {c1.Equals(c2)}");
Console.WriteLine($"record ToString: {r1}");
Console.WriteLine($"class  ToString: {c1}");

var moved = r1 with { Y = 5 };       // copy with one property changed
Console.WriteLine($"with: {moved}, original: {r1}");

var (x, y) = r1;                     // positional records deconstruct
Console.WriteLine($"deconstruct: {x} {y}");

record PointRecord(int X, int Y);
class PointClass { public int X { get; set; } public int Y { get; set; } }
EOF
dotnet run

Output

record equal: True, Equals: True
class  equal: False, Equals: False
record ToString: PointRecord { X = 1, Y = 2 }
class  ToString: PointClass
with: PointRecord { X = 1, Y = 5 }, original: PointRecord { X = 1, Y = 2 }
deconstruct: 1 2

Differences

	record (record class)	class
== and Equals	Compare property values	Compare references (same object)
GetHashCode	Based on property values	Based on identity
Positional properties	init-only, set once at construction	Declared by hand, often get; set;
with expression	Yes: copy with changes	No (C# 10+ allows with on structs and anonymous types)
ToString()	Type name and property values	Type name only
Deconstruct	Generated for positional records	Write it yourself
Inheritance	From other records only	From any class
Memory	Reference type (heap); record struct is a value type	Reference type (heap)

Which one to use

record: immutable data, values compared by content, API request and response models, events, dictionary keys.
record struct (C# 10+): small value types where you want the generated equality and ToString without heap allocations.
class: entities with identity (an EF Core entity, a service, a UI view model) and objects whose state changes over time.

Sources

errors · csharpC# warning CS8618: Non-nullable property must contain a non-null value when exiting constructorCS8618 warns that a non-nullable property or field can still be null after the constructor runs. Fix it with required, an initializer, a constructor or string?.errors · csharpC# error CS1061: does not contain a definition and no accessible extension methodC# CS1061: the type has no member with that name and no extension method fits. Fix the member name or type, or add using System.Linq. Real dotnet build output.compare · kotlinKotlin val vs var: read-only vs mutable variablesIn Kotlin, val declares a read-only reference assigned once and var a mutable one. A val object can still change inside. When to use each one, and const val.

Side by side

Differences

Which one to use

Sources

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