When to Use Struct Over Class in C#: Understanding the Differences with Examples

Category > CSHARP || Published on : Monday, March 13, 2023 || Views: 253 || C# Struct Class Value Type Reference Type Memory Usage.


C# offers two user-defined types, struct and class, that developers can use to encapsulate data and behavior. However, choosing between the two depends on the context and the specific needs of your application. This article discusses the differences between struct and class in C# and when to use them to optimize your code and improve performance.

In C#, both Struct and Class are used to create user-defined types that encapsulate data and behavior. However, there are some important differences between them that make one more suitable for certain scenarios than the other. In this article, we will explore when to use Struct over Class in C# and provide some example code to illustrate the differences.

Struct in C#

A struct is a value type that can contain data members and functions, just like a class. However, unlike a class, a struct is stored on the stack rather than the heap. This means that structs are more efficient in terms of memory usage and are ideal for small, lightweight objects.

One common use case for structs is to represent mathematical and geometric concepts such as points, vectors, and rectangles. For example, consider the following struct definition:

struct Point
{
    public int X;
    public int Y;

    public Point(int x, int y)
    {
        X = x;
        Y = y;
    }

    public override string ToString()
    {
        return $"({X}, {Y})";
    }
}

In this example, we define a Point struct that has two public integer fields X and Y, a constructor that initializes these fields, and an override of the ToString method to provide a string representation of the Point. Because a Point is a small, lightweight object, it is more efficient to store it as a struct rather than a class.

Class in C#

A class, on the other hand, is a reference type that is stored on the heap. This means that classes are less efficient in terms of memory usage but more flexible than structs. Classes can be used to represent larger, more complex objects and can be inherited and extended by other classes.

One common use case for classes is to represent entities in a game or simulation. For example, consider the following class definition:

class Entity
{
    public string Name { get; set; }
    public int Health { get; set; }
    public int Damage { get; set; }

    public Entity(string name, int health, int damage)
    {
        Name = name;
        Health = health;
        Damage = damage;
    }

    public void Attack(Entity target)
    {
        target.Health -= Damage;
    }
}

In this example, we define an Entity class that has three public properties Name, Health, and Damage, a constructor that initializes these properties, and a method Attack that reduces the health of another Entity object. Because an Entity is a larger, more complex object, it is more efficient to store it as a class rather than a struct.

When to use Struct over Class in C#

In general, you should use structs when:

  • You need to create small, lightweight objects.
  • You need to create objects that have value semantics rather than reference semantics.
  • You need to avoid heap allocation and reduce memory usage.
  • You need to create objects that are immutable.

You should use classes when:

  • You need to create larger, more complex objects.
  • You need to create objects that have reference semantics.
  • You need to create objects that can be inherited and extended.
  • You need to create objects that can be mutable.

Conclusion

In summary, structs and classes are both useful in C# for creating user-defined types that encapsulate data and behavior. Structs are more efficient in terms of memory usage and are ideal for small, lightweight objects, while classes are more flexible and can be used to represent larger, more complex objects. When deciding whether to use a struct or a class, consider the size and complexity of the object, as well as whether it needs value semantics or reference semantics.