Late Binding or Late Anything

[Piranha]

Hi,

The phrase "Late Binding". I also heard something about "Late" in
reference to a formula.

What does it mean?
How do you use it?
Why would you use it?
When would you use it?

Explaination or a reference to a place where i can get info about this
would be much appreciated.

thx
Call me Late for anything but dinner.
Dave

 

[Leith Ross]

Hi Piranha,

It's a term relating to assigning object variables. Here is some info
from the Microsoft Developers Network Site (MSDN) that should help
you.

The Visual Basic compiler performs a process called binding when an
object is assigned to an object variable. An object is early bound when
it is assigned to a variable declared to be of a specific object type.
Early bound objects allow the compiler to allocate memory and perform
other optimizations before an application executes.

By contrast, an object is late bound when it is assigned to a variable
declared to be of type Object. Objects of this type can hold references
to any object, but lack many of the advantages of early-bound objects.

You should use early-bound objects whenever possible, because they
allow the compiler to make important optimizations that yield more
efficient applications. Early-bound objects are significantly faster
than late-bound objects and make your code easier to read and maintain
by stating exactly what kind of objects are being used. Another
advantage to early binding is that it enables useful features such as
automatic code completion and Dynamic Help because the Visual Studio
..NET integrated development environment (IDE) can determine exactly
what type of object you are working with as you edit the code. Early
binding reduces the number and severity of run-time errors because it
allows the compiler to report errors when a program is compiled.

Note Late binding can only be used to access type members that are
declared as Public. Accessing members declared as Friend or Protected
Friend results in a runtime error.

Hope this answers your questions,

 

[Guest]

I don't know all there is on the subject, but

late binding requires the computer to determine what specific data type (and
properties/methods for that data type) you are using at run time, instead of
when the code is compiled.

You could declare a variable as an object, then associate it with a range
(late binding). Or, declare the variable as a range (early binding) in your
Dim statement.

As an example of late binding, you could declare a variable as an object,
then in your code set it equal to the Word Application.

Alternatively, w/early binding you would set up a reference to Word through
VBA's Tools/References menu, then declare your object variable as the Word
Application in your Dim statement. One advantage is this enables Excel's
Intellisense when you try to use Word methods and properties in your VBA code.

If I remember correctly, one possible advantage to late binding is you could
check for the presence of Word Application before associating the object
variable w/Word (or trap the error when you try to bind the object variable).
With early binding, I believe you would get a compile error before you could
try to trap the error.

 

[Guest]

One other benefit of late-binding that is not mentioned is that you do not
need to recompile your code if the object that you are referencing has
changed. If you use early binding you do need to recompile your code every
time your referenced object is updated.

Jeff

 

[Piranha]

Gentlemen,
Leith, JMB, trooper665,

Thx so much for the in depth explanation of this subject. Its more than
i hoped for.

Thx Very much
Dave