Difference between NEW and CREATEOBJECT?
 

Hi NG

Just a newbie question.

What is the difference between NEW and CREATEOBJCT ?

The following two lines of code seems to do the same!

Set xmlStr = CreateObject("Microsoft.XMLDOM")
Set xmlStr = New DOMDocument

Is there any performance issues in using the one instead of the other?

Regards
Mark

Difference between NEW and CREATEOBJECT?
 

Mark,
New uses early binding. When you declare something As the particular object
type, and use the New keyword, you are telling the compiler to go through
the specific library interface to that object. Because you've referenced
this in the VBA ToolsReferences settings, the compiler can read the typelib
file, and knows how to "talk" to that object. Because this is done at
compile time, not run time, execution is much faster.

CreateObject uses late-binding. When you declare something As Object and use
CreateObject, VBA has no idea what object you're dealing with. Thus, the
compiler has to go through the IUnknown interface. This returns an array of
pointers to all the other interfaces supported by the object. Once those
interface pointers are known, VBA then goes through IDispatch to determine
the specific property or method to actually call .All of this takes a great
deal of system overhead and can make your code execute substantially slower.

In Summary, New is quicker, and provides IntelliSense when developing, but
requires the type library to be linked.joined/referenced (whatever you want
to call it) to your project. CreateObject is slower, requires more on the
developer's part (you need to know library constant values for instance),
but can be more flexible, especially when distributing to multiple platforms
where there may be different versions of the library.

--

HTH

Bob Phillips
... looking out across Poole Harbour to the Purbecks
(remove nothere from the email address if mailing direct)

"Mark" wrote in message
...
Hi NG

Just a newbie question.

What is the difference between NEW and CREATEOBJCT ?

The following two lines of code seems to do the same!

Set xmlStr = CreateObject("Microsoft.XMLDOM")
Set xmlStr = New DOMDocument

Is there any performance issues in using the one instead of the other?

Regards
Mark

Difference between NEW and CREATEOBJECT?
 

Thanks for the detailed answer
I will then use new as often as i can

Regards
Mark

"Bob Phillips" wrote in message
...
Mark,
New uses early binding. When you declare something As the particular
object
type, and use the New keyword, you are telling the compiler to go through
the specific library interface to that object. Because you've referenced
this in the VBA ToolsReferences settings, the compiler can read the
typelib
file, and knows how to "talk" to that object. Because this is done at
compile time, not run time, execution is much faster.

CreateObject uses late-binding. When you declare something As Object and
use
CreateObject, VBA has no idea what object you're dealing with. Thus, the
compiler has to go through the IUnknown interface. This returns an array
of
pointers to all the other interfaces supported by the object. Once those
interface pointers are known, VBA then goes through IDispatch to determine
the specific property or method to actually call .All of this takes a
great
deal of system overhead and can make your code execute substantially
slower.

In Summary, New is quicker, and provides IntelliSense when developing, but
requires the type library to be linked.joined/referenced (whatever you
want
to call it) to your project. CreateObject is slower, requires more on the
developer's part (you need to know library constant values for instance),
but can be more flexible, especially when distributing to multiple
platforms
where there may be different versions of the library.

--

HTH

Bob Phillips
... looking out across Poole Harbour to the Purbecks
(remove nothere from the email address if mailing direct)

"Mark" wrote in message
...
Hi NG

Just a newbie question.

What is the difference between NEW and CREATEOBJCT ?

The following two lines of code seems to do the same!

Set xmlStr = CreateObject("Microsoft.XMLDOM")
Set xmlStr = New DOMDocument

Is there any performance issues in using the one instead of the other?

Regards
Mark

Difference between NEW and CREATEOBJECT?
 

Of course the reason to use late binding in a distributed file is to avoid
conflicts with library versions and locations. So your code doesn't error
out when the file is opened.

--
Regards,
Tom Ogilvy

"Mark" wrote in message
...
Thanks for the detailed answer
I will then use new as often as i can

Regards
Mark

"Bob Phillips" wrote in message
...
Mark,
New uses early binding. When you declare something As the particular
object
type, and use the New keyword, you are telling the compiler to go
through
the specific library interface to that object. Because you've referenced
this in the VBA ToolsReferences settings, the compiler can read the
typelib
file, and knows how to "talk" to that object. Because this is done at
compile time, not run time, execution is much faster.

CreateObject uses late-binding. When you declare something As Object and
use
CreateObject, VBA has no idea what object you're dealing with. Thus, the
compiler has to go through the IUnknown interface. This returns an array
of
pointers to all the other interfaces supported by the object. Once those
interface pointers are known, VBA then goes through IDispatch to
determine
the specific property or method to actually call .All of this takes a
great
deal of system overhead and can make your code execute substantially
slower.

In Summary, New is quicker, and provides IntelliSense when developing,
but
requires the type library to be linked.joined/referenced (whatever you
want
to call it) to your project. CreateObject is slower, requires more on
the
developer's part (you need to know library constant values for
instance),
but can be more flexible, especially when distributing to multiple
platforms
where there may be different versions of the library.

--

HTH

Bob Phillips
... looking out across Poole Harbour to the Purbecks
(remove nothere from the email address if mailing direct)

"Mark" wrote in message
...
Hi NG

Just a newbie question.

What is the difference between NEW and CREATEOBJCT ?

The following two lines of code seems to do the same!

Set xmlStr = CreateObject("Microsoft.XMLDOM")
Set xmlStr = New DOMDocument

Is there any performance issues in using the one instead of the other?

Regards
Mark