Visual Basic ( VB ) is a programming language which allows one to write procedures ( programs ) that perform operations on the spreadsheet or perform calculations that return a value.

VB is an Object Oriented language, meaning that it is designed around objects, their properties, and what they do. VBE refers to Visual Basic for Excel and it has a specific library of objects that relate to EXCEL.

For example ActiveSheet is the object by which EXCEL refers to the sheet you are currently working on. ActiveSheet.Name is a property of the active sheet (ie it's name). ActiveSheet.ActiveCell.Font is the property of the font of the active cell in the active sheet

ActiveSheet.Range(c3).Calculate is an example of a method. It specifies that the contents of cell C3 on the active sheet be calculated.

In EXCEL you can see more of these examples by going to "tools" then to "macro" then to "visual basic". In Visual basic go to "view" and then "Object Browser".

VB Procedures that perform operations on the spreadsheet are called SUBs

VB Procedures that perform calculations and return values are called FUNCTIONs

Below is an example of a SUB;

This sub changes the sign of a cell if the adjacent cell is a number and is also negative.

Sub changesign()

' Declare variables

Dim RowNum As Integer, colnum As Integer, currcell As Range, nextcol As Integer, temp As Single

RowNum = ActiveCell.Row ' intialize row number

colnum = ActiveCell.Column ' intitialize col number

nextcol = colnum + 1

Set currcell = ActiveSheet.Cells(RowNum, colnum) ' go to first cell

Set nextcell = ActiveSheet.Cells(RowNum, nextcol) ' get adjacent cell

Do While currcell.Value <> "" ' do while cell not empty

If IsNumeric(currcell.Value) Then ' is cell a number

temp = nextcell.Value

If currcell.Value < 0 Then

nextcell.Value = -1 * temp

End If

End If

RowNum = RowNum + 1

Set currcell = ActiveSheet.Cells(RowNum, colnum)

Set nextcell = ActiveSheet.Cells(RowNum, nextcol) ' get adjacent cell

Loop

End Sub

Below is an example of a FUNCTION;

This function and its related functions calculates the distance between two points on the earth's surface.

Function deltnm(lat1, long1, lat2, long2)

' This function calculates distance between two points on the earth's surface

' Point 1 is defined by lat1 long1

' Point 2 is defined by lat2, long2

' convert degrees to radians

the = 0.01745329252 * lat1

ale = 0.01745329252 * long1

ths = 0.01745329252 * lat2

als = 0.01745329252 * long2

c = Sin(the)

ak = -Cos(the)

D = Sin(ale)

e = -Cos(ale)

a = ak * e

b = -ak * D

g = -c * e

h = c * D

cp = Sin(ths)

akp = -Cos(ths)

dp = Sin(als)

ep = -Cos(als)

ap = akp * ep

bp = -akp * dp

gp = -cp * ep

hp = cp * dp

C1 = a * ap + b * bp + c * cp

29 delt = acos(C1)

33 deltkm = 6371 * delt

deltnm = deltkm * 3281 / 6076

Exit Function

End Function

Function asin(x)

asin = Atn(x / Sqr(-x * x + 1))

End Function

Function acos(x)

acos = Atn(-x / Sqr(-x * x + 1)) + 1.5708

End Function

Function atan2(x, y)

atan2 = Atn(x / y)

End Function