Usage of Classes, Structs, and Records in C#

Introduction

In the world of C# programming, choosing the right data structure can significantly impact the efficiency and readability of your code. Three fundamental constructs classes, structs, and records serve as the cornerstone for organizing and representing data. In this article, we'll delve into the nuances of each construct and explore when to use them in your C# projects.

Classes in C#

Use classes for complex data structures or entities that have behavior associated with them.
Classes are reference types, meaning they are allocated on the heap and passed by reference.
Use classes when you need inheritance, polymorphism, or when you want to implement interfaces.
Classes are suitable for representing objects with a significant amount of data or with behavior that requires methods and properties.

public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
    
    public void SayHello()
    {
        Console.WriteLine($"Hello, my name is {Name} and I am {Age} years old.");
    }
}

Structs in C#

Use structs for lightweight objects that represent simple data types.
Structs are value types, meaning they are typically allocated on the stack and passed by value.
Structs are useful for small data structures that don't require inheritance or polymorphism.
Use structs when you need high performance or when you want to avoid the overhead of heap allocation.

public struct Point
{
    public int X { get; set; }
    public int Y { get; set; }
}

Records (Introduced in C# 9.0)

Use records when you need immutable data structures with value semantics.
Records are similar to structs but provide built-in features for immutability and value-based equality.
Records are concise and convenient for defining data transfer objects (DTOs), immutable types, or value-based entities.
Records automatically generate value-based equality, hashing, and string representation methods.

public record Person(string Name, int Age);

Conclusion

Use classes for complex data structures with behavior, struct for lightweight data types, especially when performance is critical, and records for immutable data transfer objects or value-based entities. Each type has its own strengths and uses cases, so choose the one that best fits your requirements.