Constants vs. Variables

Compareing to Variable,there are several advantages by using a constant

1 The script. is easier to read

2 The script. is easier to revise

3 The script. is easier to reuse

Wrong example for variable

Option Explicit
On Error Resume Next

Dim total
Dim FirstValue
Dim SecondValue

FirstValue = 1
SecondValue = 3
Total = FirstValue + SecondValue

WScript.Echo " the total of " & FirstValue & " and " & _
  SecondValue & " Is " & (total)
FirstValue = Total
WScript.Echo " the total of " & FirstValue & " and " & _
  SecondValue & " Is " & (Total)

Executing the scripting The result is wrong like below:

C:\script.vbs H:CScript

Microsogt <R> Windows Script. Host Version 5.7

Copyright <C> Microsoft Corporation. All right reserved.

the total of 1 and 3 Is 4

the total of 4 and 3 Is 4