Variables

Variables are used to hold pieces of information which can change during the operation of a Script. They can hold either:

• Alpha-numeric character strings

  or

• Integers

 

A variable can store a single value or an array of values.

Before you can use a variable within your Script, you must declare it. This simply means that you must tell the Script about it. You do this using a 'Dim' statement.

For a single value variable, the syntax is:

Dim <variablename>

For an array variable, the syntax is:

Dim <variablename>(n)

where n is the upper bound of the array and the size of the array is n+1. For example:

Dim name(5)

would declare an array of 6 'names'.

 

You can name a variable anything you like, except the name can't start with a number or contain a full stop nor can you use the reserved words, i.e. the Event or Method names and words used in the Script statements, such as 'Dim', 'If', 'Else' etc.

 

Once you have declared a variable, you can add a value to it using the '=' operator, for example:

FirstName = "Ann"

RecNum = 0

Num1 = -1

Rtn = MyFunction(FirstName, Surname)

Totl = Number1 + Number2 '("+" is an arithmetic Operator - see Operators topic for more information)

FullName = Title + " " + FirstName + " " + Surname

Col1 = Null

or if using an array variable:

Name(3) = "John" 'sets the fourth element in the name array to "John"

Name(n) = "Alex" 'sets the (n+1)th element in the name array to "Alex"

FirstName = Name(0) 'sets the FirstName variable to the contents of the first element in the names array

 

You can declare a variable and assign a value to it on the same line if you want to, for example:

Dim Total = 0

Dim Rtn = MyFunction(Param1, Param2)

Array variables, however, must be declared and then assigned values separately, e.g. within a For … Next loop; you cannot assign values to an array within the Dim statement.

 

Variables can be limited to use within a specific Function or can be 'global', meaning they are available throughout the whole app. If you declare a variable within a Function, its use is limited to within that Function. If you declare it outside of any Function, then it will be global.

For example:

Dim FirstName

Dim Surname

 

Function OnLoad()

Dim Rtn

[code statements]

Rtn = MyFunction(FirstName, Surname)

MyFunction2()

[code statements]

End Function

In this example, the two variables FirstName and Surname are now global variables, but the Rtn variable can only be used within the OnLoad Function.