Value Type vs Reference Type

Understanding the difference between value types and reference types is essential for every C# developer. These two categories determine how variables behave in memory and how data is copied or shared across your application. Here's a clear breakdown of how they differ:

✅ Value Types

• Examples include int, bool, and char

• Cannot hold a null value

• Behave similarly to struct

• Inherit from System.ValueType

• Cannot be created with new (except for structs optionally)

• Stored directly on the stack, which makes access faster

• Copying a value type duplicates the actual value

Use them when:
You need lightweight objects with known size and value semantics, like numeric data or simple flags.

🔗 Reference Types

• Include class instances and objects

• Can be assigned a null value

• Behave like class and interface types

• Inherit from System.Object

• Created using the new keyword

• The reference is stored on the stack, but the actual data lives on the heap

• Copying a reference type copies the reference, not the actual data

Use them when:
You want to work with complex data, shared objects, or mutable states that need to be managed in memory.

🧠 Why This Matters

• With value types, changes made to a copy don't affect the original

• With reference types, changes affect all references unless explicitly cloned

• Performance and memory usage can vary depending on which one you use

• Understanding stack and heap behavior helps prevent bugs and improve performance

Always ask yourself:
Do I need to copy the value or share the object?
The answer will guide you to choose the right type.