Code Smell 51 - Double Negatives

Code Smell 51 - Double Negatives

Maxi Contieri
·Dec 24, 2020·

1 min read

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Not operator is our friend. Not not operator is not our friend.


  • Readability


  1. Name your variables, methods and classes with positive names.

Sample Code


if ( !work.isNotFinished() )
if ( work.isDone() )


This is a semantic smell. We need to detect it on code reviews.

We can tell linters to check for Regular Expressions like !not or !isNot etc as a warning.


  • Readability


Double negation is a very basic rule we learn as junior developers.

There are lots of production systems filled with this smell.

We need to trust our test coverage and make safe renames and other refactors.


More info


Photo by Daniel Herron on Unsplash

It’s harder to read code than to write it.

Joel Spolsky

This article is part of the CodeSmell Series.

Last update: 2021/06/11

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