Production RiskSoftware ResiliencyProgramming Best Practices
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]+
- one digit integer
- 0.0, .0, 0.
Note : a constant is a variable assigned only one time in its scope.
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.
Avoid litteral numeric constants.
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