Difference Between Class and Structure in C#

In C#, both classes and structures are used to define custom data types, but they have some key differences in terms of how they work, their behavior, and their best use cases. Here is the difference between class and structure in c#:

Difference Between Class and Structure in C#

Class

1. Reference Types:
   • Classes are reference types. When an instance of a class is assigned to another variable, both variables refer to the same object in memory. Changes made to one variable affect the other.
2. Inheritance:
   • Classes support single inheritance, which means a class can inherit from only one base class. This is because C# enforces a strict hierarchy through class inheritance.
3. Default Constructor:
   • Classes do not automatically provide a default parameterless constructor. You must define constructors explicitly, and you have more control over constructor overloads.
4. Nullability:
   • Class instances can be assigned the value null if they are reference types, indicating that they are not referring to any valid object in memory.
5. Complexity:
   • Classes are suitable for creating complex objects that have both data (fields) and behavior (methods). They are used to model entities with significant functionality.
6. Memory Allocation:
   • Class instances are allocated on the heap, and they require garbage collection to manage memory.

Structure

1. Value Types:
   • Structures are value types. When an instance of a structure is assigned to another variable, a copy of the entire structure is made. Changes made to one variable do not affect the other.
2. No Inheritance:
   • Structures do not support inheritance in the same way as classes. They cannot directly inherit from another class or structure.
3. Parameterless Constructor:
   • Structures automatically provide a default parameterless constructor, which initializes all fields to their default values.
4. No Nullability:
   • Structure instances cannot be assigned the value null. They always have a valid value because they are value types.
5. Simplicity:
   • Structures are suitable for small data structures that primarily hold data. They are used to model simple entities with few or no methods.
6. Memory Allocation:
   • Structure instances are allocated on the stack or inline within other objects. They do not require garbage collection.

Choosing Between Classes and Structures:

• Use a class when you need to create complex objects with behavior, inheritance, and the potential for being nullable (null).
• Use a structure when you need to create small data-centric structures that do not require inheritance, and you want to ensure value semantics (copying) instead of reference semantics.
• Consider using structures for cases where performance and memory allocation are critical concerns, as structures are allocated on the stack or inlined within other objects, reducing memory overhead.

Conclusion

Remember that choosing between classes and structures depends on your specific use case and the characteristics of the data you’re modeling.