Production RiskSoftware ResiliencyProgramming Best Practices
Production Risk
Magic Numbers are a Production Risk
This code insight counts one violation each time a litteral numeric constant is encountered, that is not assigned to a constant.
-
interger : (0|0[xX])?[0123456789ABCDEF]+([lL]?
-
decimal : ([0-9]*\.[0-9]+|[0-9]+\.)
- real : [0-9]+[eE][+-]?[0-9]+
exceptionÂ
- one digit integer
- 0.0, .0, 0.
- 1.0
Note : a constant is a variable assigned only one time in its scope.
example:
PI = 3.14 # not a violation because assigned to a constant
CONST = 123 * 456 # 2 violations : the assignation is an expression (containing 2 Magics)
a = 12 # violation because assigned to a variable
if (b):
a = b
)
Why you should care
It is recommended to use constants as default values for arguments in a function or method. This is cleaner, easier to read and there’s only one place to modify. Make sure, you document your constant, to explain where the value comes from.
Highlight :
Avoid litteral numeric constants.
Business Impacts
CAST recommendations
References
https://www.quantifiedcode.com/knowledge-base/maintainability/Use%20constants%20as%20default%20values%20for%20arguments/24kTDwfL
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