The Anchorage

Personal website of Gregory K. Maxey, Commander USN (Retired)

• Quarterdeck
• What's New
• Microsoft Word Tips
• Consulting
• Chain Locker
• Lucky Bag
• Contact
• Search

Do you have ad-blocking software enabled? While I respect your right to do so, your donations and the minimal advertisements on this site help to defray internet and other costs of providing this content. Please consider excluding this website from blocking or turning off the blocker while browsing this site.

The purpose of this Microsoft Word Tips & Microsoft Word Help page is explain and demonstrate Early and Late binding OLE Automation techniques to control and use one application from another.

Early Binding

An object is early bound when it is assigned to a variable declared to be of a specific object type (e.g., Excel.Application). Early bound objects allow the VB compiler to allocate memory and perform other optimizations before an application executes.

To use early binding, you must set a reference to the object type in your VBA project.

Use the following declaration and code to create an instance of Excel:

• Dim oXLApp as Excel.Application
• Set oXLApp = New Excel.Application

Advantages of Early Binding

• Code is compiled up front, where with late binding the code is compiled as it runs.  This allows the compiler to make important optimizations that leads to faster, more efficient code.
• Code is easier to read (you see exactly what kind of objects are being used) and therefore generally easier to maintain.
• Early binding enabled useful features such as Auto List Members (intellisense) and Dynamic Help.
• Early binding reduces the number and severity of run-time errors because it allows the compiler to report errors when a program is compiled.  Using Debug>Compile will instantly spot many syntax errors that would go unnoticed using Late binding until run-time.
• You have access to the object models constants.

Let's look at a functional example of early binding. Illustrated below is code in a Word project that:

• Gets or creates an instance of Excel.
• Adds a workbook.
• Adds text to the cell at A1.
• Auto fits (sizes) column one to display the full text.
• Adds and formats borders around the cell A1.

I am not very familiar with the Excel object model.  However, since I used early binding, I was able to leverage its advantages to create this example. For instance:

• When I typed the dot on the line following 'Add and format borders, I was able to drill down and find a method to add borders all around the range.
• Not completely familiar with the BorderAround method, when I selected it and pressed F1, I was provided dynamic help on the BorderAround method.
• When I choose to use the "Weight" parameter, once again the intelligence showed me the list of Excel constants available.

It should be clear that early binding makes it much easier to write and compile code.

Late Binding

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.

With Late binding, GetObject, CreateObject or both can be used.  For example you could get and control an instance of Excel from Word using the following declaration and code:

• Dim oXLApp as Object
• On Error Resume Next
  Set oXLApp = GetObject(, "Excel.Application") 'Uses an existing instance.
• If Err.Numnber <> 0 Then
•   Set oXLApp = CreateObject("Excel.Application") 'Creates instance.
•  End If
•  Error GoTo 0

Advantages of Late Binding

• Your code is more certain to be version-independent.  For example, if you created a Word template add-in using Word 2016 and early binding with a reference to the Excel 2016 object library as soon above, that add-in is unlikely to run if shared with a user with Word 2010.
• References add to the file size and increases the time it takes to compile.
•  In some programing environments you may not be able to create references to another application. This isn't so much an advantage, just the only option available.

Summary

Which method to use after comparing the two is a personal choice.  Personally, I typically prepare my projects using early binding in order to take advantage of the automatic code completion and dynamic help.  Then prior to publishing or distribution I shift to late binding to leverage the version independence.

That's it! I hope you have found this tips page useful and informative.

This page was last updated on March 09, 2021

Website Privacy Statement

Back to top     Back to Word Tips