Difference between Class and Structure in .NET

1. Classes are reference types and structs are value types. Since classes are reference type, a class variable can be assigned null.But we cannot assign null to a struct variable, since structs are value type.

2. When you instantiate a class, it will be allocated on the heap.When you instantiate a struct, it gets created on the stack.

3. You will always be dealing with reference to an object ( instance ) of a class. But you will not be dealing with references to an instance of a struct ( but dealing directly with them).

4. When passing a class to a method, it is passed by reference. When passing a struct to a method, it’s passed by value instead of as a reference.

5. You cannot have instance Field initializers in structs. But classes can have
For eg:

class MyClass
{
   int myVar =10; // no syntax error.
   public void MyFun( )
   {
     // statements
   }
}

struct MyStruct
{
   int myVar = 10; // syntax error.
   public void MyFun( )
   {
     // statements
   }
}

6. Classes can have explicit parameterless constructors. But structs cannot have

7. Classes must be instantiated using the new operator. But structs can be

8. Classes support inheritance.But there is no inheritance for structs. (structs don’t support inheritance polymorphism)

9. Since struct does not support inheritance, access modifier of a member of a struct cannot be protected or protected internal.

10. A class is permitted to declare a destructor. But a struct is not

12. classes are used for complex and large set data. structs are simple to use.