A magic number is a number that comes out of nowhere, and is directly used in a statement. Magic numbers are often used, for instance to limit the number of iterations of a loops, to test the value of a property, etc.


Using magic numbers may seem obvious and straightforward when you're writing a piece of code, but they are much less obvious and straightforward at debugging time.


That is why magic numbers must be demystified by first being assigned to clearly named constants before being used.


-1, 0 and 1 are not considered magic numbers.

== Noncompliant Code Example

----
Function blnCheckSize(dblParameter As Double) As Boolean
  If dblParameter > 1024 Then
    blnCheckSize = True
  End If
End Function
----

== Compliant Solution

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Function blnCheckSize(dblParameter As Double) As Boolean
  Dim threshold As Integer = 1024

  If dblParameter > threshold Then
    blnCheckSize = True
  End If
End Function
----