Word Document Properties

Part II: Learning the Ropes 
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Computers also determine a numeric type based on the amount of memory
that the data requires. VBA supports three integer types, including 
Byte
(1
byte of storage), 
Integer
(2 bytes of storage), and 
Long
(4 bytes of storage).
The extra memory stores larger numbers: 0 to 255 for 
Byte
; –32,768 to 32,767
for 
Integer
; and –2,147,483,648 to 2,147,483,647 for 
Long
. See the Data Type
Summary help topic for additional details. Listing 4-7 is an example that demon-
strates various data types.
Listing 4-7
Demonstrating the Differences in Data Type Ranges
Public Sub DataRange()
‘ Declare the numeric variables.
Dim MyInt As Integer
Dim MySgl As Single
Dim MyDbl As Double
Dim MyCur As Currency
Dim MyDec As Variant
‘ Define values for each variable.
MyInt = 30 + 0.00010001000111
MySgl = 30 + 0.00010001000111
MyDbl = 30 + 0.00010001000111
MyCur = 30 + 0.00010001000111
MyDec = CDec(30 + 0.00010001000111)
‘ Display the actual content.
MsgBox “Integer:” + TwoTab + CStr(MyInt) + _
vbCrLf + “Single:” + TwoTab + CStr(MySgl) + _
vbCrLf + “Double:” + TwoTab + CStr(MyDbl) + _
vbCrLf + “Currency:” + vbTab + CStr(MyCur) + _
vbCrLf + “Decimal:” + TwoTab + CStr(MyDec), _
vbOKOnly, _
“VBA Data Types”
End Sub
The first few variable types use standard declarations. However, notice that
you can’t declare the decimal data type directly — you must declare it as a
Variant
in VBA. See the upcoming “Working with variant data” section for
more information about the 
Variant
type. The code assigns each variable
the same value. Notice that the code must use the 
CDec
function to insert a
decimal value into the 
Variant
.
The output shown in Figure 4-3 demonstrates something interesting about
the numeric data types. Each type silently dropped any decimal data that it
couldn’t hold. This is just one of many reasons why you have to carefully
consider the numeric data type that you use.
Defining hex and octal values
Using base 10 numbers is natural. You usually don’t worry about anything
other than base 10 numbers. However, computers use base 2, or binary, 
numbers. The switch in the circuitry is either on or off — 1 or 0.
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