Question

When is memory allocated in the .NET compact framework? If there is a difference between value and reference types, please detail. Documentation or steps to confirm are appreciated.

In particular, consider this scenario…

private MyClass item;  // here?  public void MyMethod() {     item = new MyClass();  // or here? } 

Answer 1

There are 3 different ways memory is allocated.

Static:

These are bound and allocated at compile time. Global static variables for example.

Stack Dynamic:

These are bound during runtime and pushed onto the stack. Such as a local variable in a function call.

Heap Dynamic:

Now heap dynamic also has a few different ‘sub categories’ such as implicit and explicit, but I won’t go into that detail.

When you declare

private MyClass item;  // here? 

a reference to MyClass is pushed onto the stack. It is only a reference and nothing more. Its value is null at that point.

public void MyMethod() {     item = new MyClass();  // or here? } 

It is at that point where memory is explicitly allocated on the heap by calling ‘new MyClass()’ and item then references it.

So in actuality, you have 2 variables after you call MyMethod. A refernce type named item, and an unnamed variable on the heap which item references that is of type MyClass.