Records

Syntax

public record RecordName(type Prop1, type Prop2);

Examples

public record Point(int X, int Y);

Point p1 = new Point(3, 4);

Console.WriteLine(p1.X);          // 3 - auto-generated property
Console.WriteLine(p1);             // Point { X = 3, Y = 4 } - auto ToString()

Point p2 = new Point(3, 4);
Console.WriteLine(p1 == p2);       // true - value equality, unlike a class
Console.WriteLine(p1.Equals(p2));   // true

public record Point(int X, int Y);

Point original = new Point(3, 4);
Point moved = original with { X = 10 };

Console.WriteLine(original);  // Point { X = 3, Y = 4 } - unchanged
Console.WriteLine(moved);      // Point { X = 10, Y = 4 }

public record Rectangle(double Width, double Height)
{
    public double Area => Width * Height;
    public bool IsSquare => Width == Height;
}

Rectangle r = new Rectangle(5, 5);
Console.WriteLine(r.Area);       // 25
Console.WriteLine(r.IsSquare);    // true

public record Point(int X, int Y);

Point p = new Point(3, 4);
var (x, y) = p;  // deconstructs automatically

Console.WriteLine($"x={x}, y={y}");

Best practices

• Use records for simple, immutable data carriers (DTOs, value objects) instead of hand-writing a full class with Equals, GetHashCode, and ToString
• Use the with expression to create modified copies instead of mutating a record in place, which keeps the immutability guarantees intact
• Prefer records over classes whenever value-based equality (comparing by data, not reference) is what you actually want
• Remember records are reference types stored on the heap like classes - "record" describes their equality/immutability behavior, not their memory location (use record struct for a value-type record)

At a glance

Purpose

Applications on the .NET platform

File extension

.cs

Runs in

.NET runtime

Usually used with

.NET SDK and libraries

Specifications & further reading

• C# language reference

Related C# documentation