VBA-the very basic pattern

Option Explicit

Function Add(a As Double, b As Double) As Double

Dim c As Double

c = a + b

Add = c

End Function

Option explicit forces us to declare our variables before we define them.

Function Sum_Range( A As Range ) As Double

Dim total As Double

Dim r, c As Integer

For r = 1 To A.Rows.Count

For c = 1 To A.Columns.Count

total = total + A(r, c)

Next c

Next r

Sum_Range = total

End Function

Given date in cells A1 to A5, we can call this function in Excel as:

=Sum_Range( A1:A5 )

Now, let’s write a sub-routine.

Sub Sum_Values()

Dim a, b As Double

a = Range("A1").Value

b = Range("A2").Value

Range("B1").Value = a + b

End Sub

This sub-routine is a macro. An Excel macro contains instructions to be executed. We

often use macros to eliminate the need to repeat steps of common performed tasks. We

can cause this sub-routine to run using a button. To add a button to your spreadsheet,

click open View | Toolbars | Forms. From the Forms toolbar, left-click on the button icon

and paint an area on your spreadsheet. When the Assign Macro window shows up, select

Sum_Values and click OK. When you click on the button, the sum of A1 and A2 should

appear in B1.