>I wonder whether I could get some feedback on the following problems.
>
>I have a few lines of codes to create an object, use it, and release it later.
>
>o1 = createobject("my_object")
>......
>
>oCurrent = o1
>... do something with oCurrent ....
>
>o1.next = createobject("my_object")
>oCurrent = o1.next
>... do somethig with oCurrent ....
>
>&& now I try to release to objects
>release oCurrent
>release o1
>
>My questions are:
>1. does oCurrent = o1.next copy the object or just the reference of the object?

A reference is copied. Any change done on one variable will be seen as changes in the other variable.

>2. does release oCurrent release the memory acquired in 2nd createobject?

I understand an object gets destroyed as soon as there are no references to it:

o1 = CreateObject(...) && Object created (and Init() fired), one reference to object
o2 = o1 && Second reference to the same object
release o1 && Still one reference to object
release o2 && No reference to object; object gets destroyed, Destroy() is called.

I seldom release objects explicitly; note that when an object variable gets out of scope, the object gets destroyed (if there are no more references to it). However, in some situations there are cross-references that avoid objects from being destroyed ("dangling object references"). This will usually happen with properties of an object, that have a reference to another object. In this case, you can assign NULL to the property, as part of the cleanup process.

>3. does release o1 release the memory for both createobject(...) even without the release oCurrent?

As long as there are references to an object, the object remains in memory.