VBA Arrays

Most programming languages support arrays. An array is a group of variables that share a common name.

You refer to a specific variable in the array by using the array name and an index number in parentheses.

For example, you can define an array of 12 string variables to hold the names of the months of the year.

If you name the array MonthNames, you can refer to the first element of the array as MonthNames(1), the second element as MonthNames(2), and so on.

Dim MonthNames("Jan", "Feb", "Mar", "April", "May", "Jun", "July", "Aug", "Sep", "Oct", "Nov", "Dec") As string
print(MonthNames(1))    'print Feb

Declaring Arrays

Before you can use an array, you must declare it. No exceptions.

Unlike normal variables, VBA is very strict about this rule.

You declare an array with a Dim or Public statement, just as you declare a regular variable.

However, you also need to specify the number of elements in the array.

You do this by specifying the first index number, the keyword To, and the last index number — all inside parentheses.

The following example shows how to declare an array of 100 integers:

Dim MyArray(1 To 100) As Integer

When you declare an array, you can choose to specify only the upper index.

VBA assumes that 0 is the lower index. Therefore, both of the following statements declare the same 101-element array:

Dim MyArray(1 To 100) As Integer
Dim MyArray(1 To 100)

If you want VBA to assume that 1 (rather than 0) is the lower index for your arrays, include the following statement in the Declarations section of your module:

Option Base 1

This statement forces VBA to use 1 as the first index number for arrays that declare only the upper index.

If above statement is present, the following statements are identical, both declaring a 100-element array:

Dim MyArray(1 To 100) As Integer
Dim MyArray(1 To 100)

There are two other arrays

  • Multi-dimensional array

  • Dynamic array

But I don’t think these two are that much useful for use to learn hence we will not delve into them.

Next post will be about VBA Functions.