Magic numbers (MagicNumber)

Type	Scope	Severity	Activated by default	Minutes to fix	Tags
Code smell	BSL OS	Minor	Yes	1	badpractice

Parameters

Name	Type	Description	Default value
authorizedNumbers	String	allowed numbers, coma separated. Example:-1,0,1,60	-1,0,1
allowMagicIndexes	Boolean	allow magic indexes	true

Description

Magic numbers are any number in your code that does not immediately become apparent without being immersed in context.

Examples

Bad

Function GetsTheInterval(Duration)

     Return Duration < 10 * 60 * 60;

End Function

Good

Function GetsTheInterval (Duration in Seconds)

    MinutesHour     = 60;
    SecondsMinute   = 60;
    SecondsHour     = SecondsMinute * MinutesHour;
    HoursIninterval = 10;
    Return Duration < HoursWininterval * SecondsHour;

End Function

Exceptions

Magic numbers used in structures and correspondences are not considered errors, as they are used as keys or values in data structures where the context is clear:

// Structure insert - no error
Structure = New Structure;
Structure.Insert("MyVariable", 20); // No error
Structure.Insert("AnotherVariable", 42); // No error

// Structure constructor - no error
Structure2 = New Structure("Field1, Field2", 5, 15); // No error

// Direct structure property assignment - no error
StructureWithFields = New Structure("MyVariable, AnotherField");
StructureWithFields.MyVariable = 20; // No error
StructureWithFields.AnotherField = 50; // No error

// Fixed structure - no error
FixedStructure = New FixedStructure("Value", 200); // No error

// Correspondence - no error (both key and value)
Correspondence = New Correspondence;
Correspondence.Insert("Code", 123); // No error
Correspondence.Insert(1980, "Olympics in Moscow"); // No error

Snippets

Diagnostic ignorance in code

// BSLLS:MagicNumber-off
// BSLLS:MagicNumber-on

Parameter for config

"MagicNumber": {
    "authorizedNumbers": "-1,0,1",
    "allowMagicIndexes": true
}