Code Smell 03 - Functions Are Too Long

Humans get bored beyond line 10.

TL;DR: Refactor and extract functions longer than 5 lines.

Problems

• Low Cohesion
• High coupling
• Difficult to read
• Low Reuse

Solutions

1) Refactor

2) Create small objects dealing with some tasks. Unit test them.

3) Compose methods

Examples

• Libraries

Sample Code

Wrong

<?

function setUpChessBoard() {

    $this->placeOnBoard($this->whiteTower);
    $this->placeOnBoard($this->whiteKnight);
    //A lot of lines
    //.....
    $this->placeOnBoard($this->blackTower);
}

Right

<?

function setUpChessBoard() {
    $this->placeWhitePieces();
    $this->placeBlackPieces();
}

Detection

All linters can measure and warn when methods are larger than a predefined threshold.

Relations

Also Known as

• Long Method

More info

• Refactoring Guru

Tags

• Complexity

Conclusion

Extract long method into smaller pieces. Break complex algorithms in parts. You can also unit test these parts.

Credits

Photo by Hari Panicker on Unsplash

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Programs are meant to be read by humans and only incidentally for computers to execute.

Donald Knuth

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

Last update: 2021/06/01

Comments

[JoelBonetR 🥇]

The funny thing is that placeWhitePieces() and placeBlackPieces() will need to call each placement inside which then we'll need to separate into single functions placeKing($this) and get $this->color inside to keep them atomic.
So it's just a matter of ordering the code at the end.

[Maxi Contieri]

as always :)

[Winston Puckett]

A developer I really respect said, "a developer can only hold one screen's worth of code at one time." And sets the function limit according to how big the average developer's screens are. I also like the way you said it, "humans get bored beyond line 10."

[Eduardo Luz]

Sorry, but at first glance I didn't see any difference among the right and wrong code.