Senin, 11 April 2016

Visual Basic for Applications Excel Terminology

Explanation Have you ever wanted to customize Excel? For example, you might want to display a dialog box asking a user to enter specific data for a worksheet. 
Maybe you want to perform a decision-based task, such as displaying a message when a user activates a worksheet. You can do these things, and more, by programming in Visual Basic for Applications (VBA).
VBA is a programming language that’s part of the Microsoft Office suite. You can use VBA to create programs that work within Microsoft Office applications, such as Microsoft Excel and Microsoft Word. 
VBA is based on the concept of Object-Oriented Programming (OOP). OOP is a programming concept in which all the elements of a program are considered as objects.
VBA makes decision-based tasks easier, because its code can execute automatically in response to an action. For example, you can write VBA code to accept values and prompt the user to enter values if mandatory fields are skipped, ensuring the integrity of your data. 

VBA terminology
Using VBA, you can directly access objects to control and manipulate the behavior of the application. However, before you start coding in VBA, you need to be familiar with some key terms associated with it.
The following table describes some of these terms:

Term and Description
Any element of an application with specific characteristics and behavior. It’s a component that combines code and data. For example, workbooks, worksheets, ranges, and charts are all objects.
A characteristic or named attribute of an object. For example, Name and StandardWidth are the properties of the Worksheet object.
A behavior or action that’s performed by an object. For example, Calculate is a method that updates the values in a Worksheet object containing formulas.
A named sequence of instructions that performs a specific task. For example, you can create a procedure to save the changes made before closing a workbook.
A line of text within a procedure, which you use to describe each line of code or the entire procedure. Comments always start with an apostrophe.
A file in which you can write and edit procedures and other VBA codes.

Collection and container objects

Objects can be either collection objects or container objects. 

A collection object 
is a set of related objects having the same properties. For example, the Worksheets collection object represents all the worksheets in a workbook.
A container object 
contains one or more objects, which may or may not be related. For example, Workbook is a container object that contains the Worksheet objects. The outermost container object is the Application object that contains all other Excel objects, such as Worksheets and Workbooks.

VBA and macros
Macros that you create and record using the Excel interface are written by Excel using VBA code. But there’s a difference between macros and VBA procedures that you write from scratch. 
A macro performs a set of instructions, then stops. For this reason, macros are very useful for automating repetitive tasks.
But macros follow a single execution path. A procedure written in VBA code can evaluate conditions, make decisions based on those conditions, and then alter the flow of execution.

Do it! 
A-1: Discussing VBA Questions and answers
1 What’s the main advantage of VBA compared to macros?
VBA code can evaluate conditions, make decisions, and then execute automatically in response to those decisions. Recorded macros can only follow a single execution path.
2 Lets say you want to purchase a car. You can select a yellow, red, or black one. Identify the object and its property in this case.
The car is the object 
The color is the property
3 What’s a procedure?

A procedure is a named  set of instructions that performs specified actions. For example, you can write a procedure that saves changes made before closing an Excel workbook.

4 You want a worksheet name to change automatically when text is entered in a specific cell. Would you record a macro or use VBA? Why?
You’d use VBA, because the code used to change the name would run automatically when the user enters text in a cell.

Tidak ada komentar:

Posting Komentar

Catatan: Hanya anggota dari blog ini yang dapat mengirim komentar.