C# Enums, Records, Structs, and Classes

A string status can contain "paid", "Paid", "padi", or any other text. When the domain has a small closed set of choices, an enum gives each choice a name and lets the compiler reject unknown members.

Enums are represented by integral values underneath, but do not treat arbitrary integers as automatically valid enum members. Validate values parsed from external input, and avoid relying on numeric order unless the domain explicitly defines it.

OrderStatus status = OrderStatus.Shipped;

switch (status)
{
  case OrderStatus.Pending:
      Console.WriteLine("Await payment");
      break;
  case OrderStatus.Paid:
      Console.WriteLine("Pack order");
      break;
  case OrderStatus.Shipped:
      Console.WriteLine("Track delivery");
      break;
  case OrderStatus.Cancelled:
      Console.WriteLine("No action");
      break;
}

Two bank accounts with the same balance are not the same account; identity matters. Two coordinate values with the same X and Y usually represent the same coordinate; their contained values matter. Type choice should follow that semantic question before performance folklore.

Classes use reference identity for default equality unless they override it. Records are designed for data-centric models and synthesize value-based equality from their components. Modern records also support concise non-destructive copying with with expressions.

// Modern C# / current .NET SDK example
public record ShippingAddress(string City, string Country);

ShippingAddress first = new ShippingAddress("Jeddah", "Saudi Arabia");
ShippingAddress second = new ShippingAddress("Jeddah", "Saudi Arabia");

Console.WriteLine(first == second); // True: same component values

A struct is a value type. Assigning it to another variable copies its current value. Structs work well for small value-like concepts such as coordinates, ranges, or measurements, especially when immutable. Large or highly mutable structs create surprising copies and are usually a poor fit.

A record struct combines value-type copying with record-style generated value equality. A record class remains a reference type. The word record describes data-oriented behavior; it does not by itself tell you whether storage uses value or reference semantics.

An enum is not ideal when choices are configured at runtime or each option has substantial changing behavior. A lookup table or polymorphic objects may model those cases better. A record is not automatically immutable if its members are mutable; design the member types and accessors accordingly.

Start with the simplest representation that preserves valid states and equality meaning. Changing a public type later can affect callers, so spend a moment on semantics, but do not create elaborate hierarchies for imagined future requirements.