TL;DR: Don't leave commented code. Remove it.

Problems

• Readability

• Dead Code

• Lack of Coverage

• Lack of Source Version Control

Solutions

1. Remove commented code

2. Implement Source Version Control

Context

When debugging code we tend to comment on code to see what happens.

As a final step, after all our tests pass, we must remove them following clean code practices.

Sample Code

Wrong

function arabicToRoman(num) {
  var decimal = [1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1];
  var roman = ['M', 'CM', 'D', 'CD', 'C', 'XC', 'L', 'XL', 'X', 'IX', 'V', 'IV', 'I'];
  var result = '';

  for(var i = 0; i < decimal.length; i++) {
    // print(i)
    while(num >= decimal[i]) {
      result += roman[i];
      num -= decimal[i];
    }    
  }
  // if (result > 0 return ' ' += result)

 return result;
}

Right

function arabicToRoman(arabicNumber) {
  var decimal = [1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1];
  var roman = ['M', 'CM', 'D', 'CD', 'C', 'XC', 'L', 'XL', 'X', 'IX', 'V', 'IV', 'I'];
  var romanString = '';

  for(var i = 0; i < decimal.length; i++) {
    while(arabicNumber >= decimal[i]) {
      romanString += roman[i];
      num -= decimal[i];
    }    
  }

 return romanString;
}

Detection

[X] Semi-Automatic

Some machine learning analyzers can detect or parse comments and guide as to remove them.

Tags

• Comments

Conclusion

We need to remove all commented-out code.

Relations

Refactorings

Credits

Photo by maxim bober on Unsplash

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Don’t document the problem, fix it.

Atli Björgvin Oddsson

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This article is part of the CodeSmell Series.