A litttle confused about structs and reference types

notig · September 25th, 2010, 10:18 AM

In the book it says "everything is an object" .

In chapter 9 it says "structs are value types" , "classes are reference types"

then it says "objects are reference types"

so are structs not objects?

ChristianNagel · October 1st, 2010, 08:35 AM

All the statements are true, but I agree confusing :-)
Structs are objects when they are used as an object. This is known "boxing". If a struct is used as an object, it is boxed.
One small example:
int is a struct and thus a value type. Declaring and instantiating an int:

Code:

int x = 3;

Now assigning the int to an object, boxing happens:

Code:

object o = x;

Boxing also happens if an int is passed to a method that accepts an object parameter.
Page 303-305 gives more information on boxing.

Hope this helps.