Be consistent with the parameters you use. Code is prose.

TL;DR: Don't confuse you readers. Keep the order.

Problems

• Readability

• Consistency

Solutions

1. Refactor and change parameters order.

2. Use named parameters

Sample Code

Wrong

function giveFirstDoseOfVaccine(person, vaccine) {
  //
}

function giveSecondDoseOfVaccine(vaccine, person) {
  //
}


giveFirstDoseOfVaccine(jane, pfizer);
giveSecondDoseOfVaccine(jane, pfizer);  //Unnoticed mistake

Right

function giveFirstDoseOfVaccine(person, vaccine) {
  //
}

function giveSecondDoseOfVaccine(person, vaccine) {
  //
}


giveFirstDoseOfVaccine(jane, pfizer);
giveSecondDoseOfVaccine(jane, pfizer);  //jane is immunized

Detection

• Some very smart linters may be able to compare arguments and hint for possible mistakes.

Tags

• Readability

Conclusion

This is a very simple smell.

Readability is very important to avoid mistakes.

Relations

Credits

Photo by Lance Grandahl on Unsplash

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Computers are good at following instructions, but not at reading your mind.

Donald Knuth

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This article is part of the CodeSmell Series.