Understanding Variables

Macros are written in a language called Visual Basic for Applications (VBA). VBA allows you to use quite a few different types of variables. Variables are nothing but names that represent other data. In general, you can store either numbers or characters in VBA variables. The language provides eleven specific 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 2 billion characters to a string variable in Word 2000 or later, or approximately 63,000 characters in Word 97.
• 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. 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 WordTip, 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. (The Dim statement is used to declare the data type to be used for a variable.)