Understanding Variables in VBA Macros

Excel allows you to write macros in a language called Visual Basic for Applications (VBA). This is a specialized version of the BASIC programming language, and as such, allows you to use variables. Variables are nothing but names which represent other data. During the course of your macro you can even change the data to which the name applies.

VBA allows you to use quite a few different types of variables. There are eleven types of variables you can use in your macros. These are known as data types, and you should use the data type that most closely matches the characteristics of the information you are storing in the variable. VBA supports the following data types:

• Byte. A numeric variable within the range of 0 to 255.
• Boolean. A variable with two possible values: True (-1) or False (0).
• Integer. A numeric variable designed for whole numbers in the range of -32,768 to 32,767.
• Long. A numeric variable designed for very large whole numbers.
• Currency. A numeric variable designed for calculations involving monetary values.
• Single. A numeric variable designed for single-precision floating-point values; accurate to about six or seven decimal places.
• Double. A numeric variable designed for double-precision floating-point values; accurate to about 15 decimal places.
• Date. A numeric variable designed to represent a date and time as a real number. The value to the left of the decimal point is the date, and that portion to the right of the decimal point is the time.
• String. A variable that can contain any type of text or character you desire. You can assign a maximum of approximately 63,000 characters to a string variable.
• Object. A variable that contains a pointer to a defined object within VBA.
• Variant. A variable that can contain any type of data.

An additional data type (Decimal) is also specified in the VBA documentation, but is not currently supported by the language. As in other versions of BASIC, VBA also allows you to define variable arrays and you can also create user-defined data types. The full range of variable specifications is much too complex for a simple ExcelTip, however. If you need specific information about how to work with variables, refer to a good Visual Basic or VBA programming book. You can also look in the VBA on-line help under the Dim statement.