Code Smell 219 - Looping from index 0

Counting from zero seems natural. Doesn't it?

TL;DR: Start counting from one instead of zero. Like humans do.

Problems

• Bijection from real-world broken

• Cognitive load

• Overly implementation-oriented code

Solutions

1. Favor high-level declarative languages

Context

Low-level languages force you to think at a machine level.

Hardware turning machines were designed to use binary gates and start indexing at 0.

A few programming languages use one-based indexing, where indexing starts from 1.

These languages are known for being higher level and more declarative:

• Basic / Visual Basic
• Pascal
• Smalltalk
• Fortran
• Lua
• MATLAB
• R
• Julia

Sample Code

Wrong

package main

import "fmt"

func main() {    
    numbers := []int{10, 20, 30, 40, 50}

    for i := 0; i < len(numbers); i++ {
        // Iteration goes from zero to len-1
        fmt.Println(numbers[i])
    }
}

Right

numbers = [10, 20, 30, 40, 50];

% Looping through the array using one-based indexing
% from 1 to length
for currentIndex = 1:length(numbers)
    disp(numbers(currentIndex));
end

Detection

[X] Automatic

This is a language smell.

Exceptions

• Low-level optimized code

Tags

• Declarative Code

Conclusion

We need to think as humans when we code and not as machines.

Humans count from one.

Zero number was a brilliant discovery in math and science but it does not apply to everyday counting.

Relations

Code Smell 53 - Explicit Iteration

Maxi Contieri ・ Jan 5 '21

#codenewbie #webdev #cleancode #tutorial

Code Smell 123 - Mixed 'What' and 'How'

Maxi Contieri ・ Mar 22 '22

More Info

Wikipedia

Disclaimer

Code Smells are my opinion.

Credits

Photo by Andy Kelly on Unsplash

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Pay attention to zeros. If there is a zero, someone will divide by it.

Cem Kaner

Software Engineering Great Quotes

Maxi Contieri ・ Dec 28 '20

#codenewbie #programming #quotes #software

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This article is part of the CodeSmell Series.

How to Find the Stinky parts of your Code

Maxi Contieri ・ May 21 '21

#codenewbie #tutorial #codequality #beginners

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My new book about clean code is available for pre-order.

You will find several recipes like this one with a higher level of detail