CS1100 Computer Science and its Applications
CS1100 1

• A macro is a set of instructions that tells Excel to perform one or more actions
• An Excel macro is like a computer program but it runs completely within Excel.
• Used to automate tedious or frequently repeated tasks
– Macro can carry out sequence of actions much more quickly

• Save time – even if you are an expert Excel user, the computer can beat you every time
• Reduce errors – if the instructions are correct, programs do not make mistakes
• Enforce standards – for example, each sales rep may be required to submit a weekly summary spreadsheet that follows a specific structure and format

• Two ways to create a macro:
– Record it using the Macro Recorder
– Build by typing instructions in a VBA (Visual Basic for Applications) module (beyond the scope of this course)
– These two approaches can be combined

• Macro code can be used for evil too
• VBA macros included in Microsoft Office documents (usually attached in emails) have contained viruses in the past
– macro programs embedded in documents can be run automatically when the document is opened, a mechanism which can spread viruses.
• To configure security settings:
– File  Options  Excel Options  Trust Center
 Trust Center Settings

• One famous macro virus called Melissa, released in March, 1999:
– The virus sent a file called “List.doc” which it claimed had passwords to 80 adult websites.
– Anyone who opened the document would get a free copy of the Melissa macro virus.
– Melissa would then gather the first fifty entries in the address book, and email itself to all of them.
– Melissa infected so many systems that by March 26th, it was shutting down mail servers with all of the infected emails traveling across the net.

• Click on the File tab of the ribbon to open the File menu
• Click on Options to open the Excel Options dialog box.
• Click on the Customize Ribbon option in the left hand window
• Under the Main Tabs section of the options window, check off the Developer option.
• Click OK the Developer tab should now be visible

• The Excel default workbook format (.xlsx) does not support macros
• To save a workbook containing macros, you need to use one of the following formats:
– .xlsm
– .xlsb
– .xls

• The recorder allows you to create macros without knowing VBA
• Best to plan your macro before starting the recorder
• If you’re curious about VBA and want to learn to do more with macros, the recorder can be a great learning tool
– You can examine the code that the recorder generates and edit it.

• 4 options to complete in this dialog box:
– Macro name - give your macro a descriptive name. The name must begin with a letter and have no spaces. Only letters, numbers and underscore permitted.
– Shortcut key - (optional) fill in a letter, number, or other character in the available space. This will allow you to run the macro by holding down the CTRL key and pressing the chosen letter on the keyboard.
– Store macro in:
• This workbook: the macro is available only in this file.
• New workbook: this option opens a new Excel file and the macro is only available in the new file.
• Personal macro workbook: this creates a hidden file
Personal.xls which stores your macros and makes them available in all Excel files
– Description: (optional) enter a description of the macro

• Create a macro that automates the formatting for a heading for the Atlantic Music Company:

• An Excel macro is written in the Visual Basic for Applications (VBA) programming language.
• Clicking on either the Edit or Step Into buttons in the Macro dialog box starts the VBA editor
• Using the VBA editor and covering the VBA programming language is beyond the scope of this class.

• By default a macro is recorded with absolute references.
– If you are in Cell A1 when you record a macro, the action will play back in A1
• To record with relative references, click Use Relative References
• Now the macro plays back in the selected cell.

• Let’s create a macro that automates the format for a monthly sales summary: