{"id":1131,"date":"2013-09-08T22:01:22","date_gmt":"2013-09-08T21:01:22","guid":{"rendered":"https:\/\/www.entropywins.wtf\/blog\/?p=1131"},"modified":"2018-09-08T04:41:26","modified_gmt":"2018-09-08T03:41:26","slug":"clean-functions","status":"publish","type":"post","link":"https:\/\/www.entropywins.wtf\/blog\/2013\/09\/08\/clean-functions\/","title":{"rendered":"Clean functions"},"content":{"rendered":"
\n

Last week I gave a presentation titled \u201cClean functions\u201d<\/a> to my Wikidata<\/a> colleagues. As the title suggests, this presentation is all about how to create clean functions that are easy to understand and modify.<\/p>\n

Why did I go with this particular design topic rather then one of the dozens of other ones I could have talked about? And why a talk on functions \u2013 everyone know how to write functions no?<\/p>\n

During the last few weeks I\u2019ve been paying attention to the complexity of code arising from violating very simple function design guidelines. During code review, I encountered many such occurrences, essentially all of them for no good reason whatsoever. That is really a pity, as this complexity ends up being costly in many ways. It slows down development considerably and increases the likelihood of defects. All while this can easily be avoided by following simple rules. Hence this presentation goes over the rules and the problems they prevent.<\/p>\n

A lot of the material in the presentation is based on works by Robert C. Martin (yes I know, I\u2019m such a fanboy), in particular his book Clean Code<\/a> and an episode from his Clean Coders<\/a> video series.<\/p>\n

Since the slides of my presentation are not designed for standalone use, they are only suitable for giving you a quick idea on what the presentation is about. I can however recommend the Clean Code III: Functions<\/a> talk by \u2026, well, you can guess that.<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

Last week I gave a presentation titled \u201cClean functions\u201d to my Wikidata colleagues. As the title suggests, this presentation is…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[8],"tags":[331,328,400,200,365,396],"class_list":["post-1131","post","type-post","status-publish","format-standard","hentry","category-software","tag-architecture","tag-clean-code","tag-functions","tag-presentation","tag-software-craftsmanship","tag-solid"],"yoast_head":"\nClean functions - Blog of Jeroen De Dauw<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.entropywins.wtf\/blog\/2013\/09\/08\/clean-functions\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Clean functions - Blog of Jeroen De Dauw\" \/>\n<meta property=\"og:description\" content=\"Last week I gave a presentation titled \u201cClean functions\u201d to my Wikidata colleagues. As the title suggests, this presentation is…\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.entropywins.wtf\/blog\/2013\/09\/08\/clean-functions\/\" \/>\n<meta property=\"og:site_name\" content=\"Blog of Jeroen De Dauw\" \/>\n<meta property=\"article:published_time\" content=\"2013-09-08T21:01:22+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2018-09-08T03:41:26+00:00\" \/>\n<meta name=\"author\" content=\"Jeroen\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@https:\/\/twitter.com\/JeroenDeDauw\" \/>\n<meta name=\"twitter:site\" content=\"@JeroenDeDauw\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Jeroen\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minute\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/www.entropywins.wtf\\\/blog\\\/2013\\\/09\\\/08\\\/clean-functions\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.entropywins.wtf\\\/blog\\\/2013\\\/09\\\/08\\\/clean-functions\\\/\"},\"author\":{\"name\":\"Jeroen\",\"@id\":\"https:\\\/\\\/www.entropywins.wtf\\\/blog\\\/#\\\/schema\\\/person\\\/4e2ef14f2ca7dc3a0ac137d1692b66b7\"},\"headline\":\"Clean functions\",\"datePublished\":\"2013-09-08T21:01:22+00:00\",\"dateModified\":\"2018-09-08T03:41:26+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/www.entropywins.wtf\\\/blog\\\/2013\\\/09\\\/08\\\/clean-functions\\\/\"},\"wordCount\":244,\"commentCount\":2,\"publisher\":{\"@id\":\"https:\\\/\\\/www.entropywins.wtf\\\/blog\\\/#\\\/schema\\\/person\\\/4e2ef14f2ca7dc3a0ac137d1692b66b7\"},\"keywords\":[\"Architecture\",\"Clean Code\",\"Functions\",\"Presentation\",\"Software Craftsmanship\",\"SOLID\"],\"articleSection\":[\"Software\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/www.entropywins.wtf\\\/blog\\\/2013\\\/09\\\/08\\\/clean-functions\\\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/www.entropywins.wtf\\\/blog\\\/2013\\\/09\\\/08\\\/clean-functions\\\/\",\"url\":\"https:\\\/\\\/www.entropywins.wtf\\\/blog\\\/2013\\\/09\\\/08\\\/clean-functions\\\/\",\"name\":\"Clean functions - Blog of Jeroen De Dauw\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.entropywins.wtf\\\/blog\\\/#website\"},\"datePublished\":\"2013-09-08T21:01:22+00:00\",\"dateModified\":\"2018-09-08T03:41:26+00:00\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/www.entropywins.wtf\\\/blog\\\/2013\\\/09\\\/08\\\/clean-functions\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/www.entropywins.wtf\\\/blog\\\/2013\\\/09\\\/08\\\/clean-functions\\\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/www.entropywins.wtf\\\/blog\\\/2013\\\/09\\\/08\\\/clean-functions\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/www.entropywins.wtf\\\/blog\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Clean functions\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/www.entropywins.wtf\\\/blog\\\/#website\",\"url\":\"https:\\\/\\\/www.entropywins.wtf\\\/blog\\\/\",\"name\":\"Entropy Wins\",\"description\":\"A blog on Software Architecture, Design and Craftsmanship\",\"publisher\":{\"@id\":\"https:\\\/\\\/www.entropywins.wtf\\\/blog\\\/#\\\/schema\\\/person\\\/4e2ef14f2ca7dc3a0ac137d1692b66b7\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/www.entropywins.wtf\\\/blog\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":[\"Person\",\"Organization\"],\"@id\":\"https:\\\/\\\/www.entropywins.wtf\\\/blog\\\/#\\\/schema\\\/person\\\/4e2ef14f2ca7dc3a0ac137d1692b66b7\",\"name\":\"Jeroen\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/d62e6b5b8e332335cf17854fac850d9c70ba367c4692872613c3110ebd4e009b?s=96&d=mm&r=g\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/d62e6b5b8e332335cf17854fac850d9c70ba367c4692872613c3110ebd4e009b?s=96&d=mm&r=g\",\"contentUrl\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/d62e6b5b8e332335cf17854fac850d9c70ba367c4692872613c3110ebd4e009b?s=96&d=mm&r=g\",\"caption\":\"Jeroen\"},\"logo\":{\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/d62e6b5b8e332335cf17854fac850d9c70ba367c4692872613c3110ebd4e009b?s=96&d=mm&r=g\"},\"sameAs\":[\"https:\\\/\\\/www.linkedin.com\\\/in\\\/jeroendedauw\\\/\",\"https:\\\/\\\/x.com\\\/https:\\\/\\\/twitter.com\\\/JeroenDeDauw\"]}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Clean functions - Blog of Jeroen De Dauw","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.entropywins.wtf\/blog\/2013\/09\/08\/clean-functions\/","og_locale":"en_US","og_type":"article","og_title":"Clean functions - Blog of Jeroen De Dauw","og_description":"Last week I gave a presentation titled \u201cClean functions\u201d to my Wikidata colleagues. As the title suggests, this presentation is…","og_url":"https:\/\/www.entropywins.wtf\/blog\/2013\/09\/08\/clean-functions\/","og_site_name":"Blog of Jeroen De Dauw","article_published_time":"2013-09-08T21:01:22+00:00","article_modified_time":"2018-09-08T03:41:26+00:00","author":"Jeroen","twitter_card":"summary_large_image","twitter_creator":"@https:\/\/twitter.com\/JeroenDeDauw","twitter_site":"@JeroenDeDauw","twitter_misc":{"Written by":"Jeroen","Est. reading time":"1 minute"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.entropywins.wtf\/blog\/2013\/09\/08\/clean-functions\/#article","isPartOf":{"@id":"https:\/\/www.entropywins.wtf\/blog\/2013\/09\/08\/clean-functions\/"},"author":{"name":"Jeroen","@id":"https:\/\/www.entropywins.wtf\/blog\/#\/schema\/person\/4e2ef14f2ca7dc3a0ac137d1692b66b7"},"headline":"Clean functions","datePublished":"2013-09-08T21:01:22+00:00","dateModified":"2018-09-08T03:41:26+00:00","mainEntityOfPage":{"@id":"https:\/\/www.entropywins.wtf\/blog\/2013\/09\/08\/clean-functions\/"},"wordCount":244,"commentCount":2,"publisher":{"@id":"https:\/\/www.entropywins.wtf\/blog\/#\/schema\/person\/4e2ef14f2ca7dc3a0ac137d1692b66b7"},"keywords":["Architecture","Clean Code","Functions","Presentation","Software Craftsmanship","SOLID"],"articleSection":["Software"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/www.entropywins.wtf\/blog\/2013\/09\/08\/clean-functions\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/www.entropywins.wtf\/blog\/2013\/09\/08\/clean-functions\/","url":"https:\/\/www.entropywins.wtf\/blog\/2013\/09\/08\/clean-functions\/","name":"Clean functions - Blog of Jeroen De Dauw","isPartOf":{"@id":"https:\/\/www.entropywins.wtf\/blog\/#website"},"datePublished":"2013-09-08T21:01:22+00:00","dateModified":"2018-09-08T03:41:26+00:00","breadcrumb":{"@id":"https:\/\/www.entropywins.wtf\/blog\/2013\/09\/08\/clean-functions\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.entropywins.wtf\/blog\/2013\/09\/08\/clean-functions\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/www.entropywins.wtf\/blog\/2013\/09\/08\/clean-functions\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.entropywins.wtf\/blog\/"},{"@type":"ListItem","position":2,"name":"Clean functions"}]},{"@type":"WebSite","@id":"https:\/\/www.entropywins.wtf\/blog\/#website","url":"https:\/\/www.entropywins.wtf\/blog\/","name":"Entropy Wins","description":"A blog on Software Architecture, Design and Craftsmanship","publisher":{"@id":"https:\/\/www.entropywins.wtf\/blog\/#\/schema\/person\/4e2ef14f2ca7dc3a0ac137d1692b66b7"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.entropywins.wtf\/blog\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":["Person","Organization"],"@id":"https:\/\/www.entropywins.wtf\/blog\/#\/schema\/person\/4e2ef14f2ca7dc3a0ac137d1692b66b7","name":"Jeroen","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/secure.gravatar.com\/avatar\/d62e6b5b8e332335cf17854fac850d9c70ba367c4692872613c3110ebd4e009b?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/d62e6b5b8e332335cf17854fac850d9c70ba367c4692872613c3110ebd4e009b?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/d62e6b5b8e332335cf17854fac850d9c70ba367c4692872613c3110ebd4e009b?s=96&d=mm&r=g","caption":"Jeroen"},"logo":{"@id":"https:\/\/secure.gravatar.com\/avatar\/d62e6b5b8e332335cf17854fac850d9c70ba367c4692872613c3110ebd4e009b?s=96&d=mm&r=g"},"sameAs":["https:\/\/www.linkedin.com\/in\/jeroendedauw\/","https:\/\/x.com\/https:\/\/twitter.com\/JeroenDeDauw"]}]}},"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p74TBF-if","jetpack-related-posts":[{"id":2392,"url":"https:\/\/www.entropywins.wtf\/blog\/2018\/10\/30\/readable-functions-do-one-thing\/","url_meta":{"origin":1131,"position":0},"title":"Readable Functions: Do One Thing","author":"Jeroen","date":"2018-10-30","format":false,"excerpt":"Several tricks and heuristics that I apply to write easy to understand functions keep coming up when I look at other people their code. This post outlines the second key principle. The first principle is Minimize State. Following posts will contain specific tips and tricks, often building on these two\u2026","rel":"","context":"In \"Clean Code\"","block_context":{"text":"Clean Code","link":"https:\/\/www.entropywins.wtf\/blog\/tag\/clean-code\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":2407,"url":"https:\/\/www.entropywins.wtf\/blog\/2019\/01\/14\/readable-functions-guard-clause\/","url_meta":{"origin":1131,"position":1},"title":"Readable Functions: Guard Clause","author":"Jeroen","date":"2019-01-14","format":false,"excerpt":"Guard Clauses are one of my favorite little tricks that allow simplifying code. A guard clause is an if statement with a return in it. Consider the following code: function doThing() { var $thing = 'default'; if (someCondition()) { $thing = 'special case'; } return $thing; } Using a Guard\u2026","rel":"","context":"In "Programming"","block_context":{"text":"Programming","link":"https:\/\/www.entropywins.wtf\/blog\/category\/programming\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":1145,"url":"https:\/\/www.entropywins.wtf\/blog\/2013\/11\/15\/presentation-the-s-in-stupid\/","url_meta":{"origin":1131,"position":2},"title":"Presentation: The S in STUPID","author":"Jeroen","date":"2013-11-15","format":false,"excerpt":"In about two weeks, I will be giving a presentation about static code at 0\u00d720, the Gent hackerspace. This is a follow up on the Clean Functions presentation I gave there about\u00a0 a month ago. Like that one, \u201cThe S in STUPID\u201d is all about how to write clean code\u2026","rel":"","context":"In "Software"","block_context":{"text":"Software","link":"https:\/\/www.entropywins.wtf\/blog\/category\/software\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":2374,"url":"https:\/\/www.entropywins.wtf\/blog\/2018\/10\/24\/readable-functions-minimize-state\/","url_meta":{"origin":1131,"position":3},"title":"Readable Functions: Minimize State","author":"Jeroen","date":"2018-10-24","format":false,"excerpt":"Several tricks and heuristics that I apply to write easy to understand functions keep coming up when I look at other peoples code. In this post I share the first of two key principles to writing readable functions. Follow up posts will contain the second key principle and specific tricks,\u2026","rel":"","context":"In "Programming"","block_context":{"text":"Programming","link":"https:\/\/www.entropywins.wtf\/blog\/category\/programming\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":1841,"url":"https:\/\/www.entropywins.wtf\/blog\/2016\/11\/24\/rewriting-the-wikimedia-deutschland-funrdraising\/","url_meta":{"origin":1131,"position":4},"title":"Rewriting the Wikimedia Deutschland fundraising","author":"Jeroen","date":"2016-11-24","format":false,"excerpt":"Last year we rewrote the Wikimedia Deutschland fundraising software. In this blog post I'll give you an idea of what this software does, why we rewrote it and the outcome of this rewrite. The application Our fundraising software is a homegrown PHP application. Its primary functions are donations and membership\u2026","rel":"","context":"In "Programming"","block_context":{"text":"Programming","link":"https:\/\/www.entropywins.wtf\/blog\/category\/programming\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.entropywins.wtf\/blog\/wp-content\/uploads\/2016\/11\/lloc-per-global.png?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.entropywins.wtf\/blog\/wp-content\/uploads\/2016\/11\/lloc-per-global.png?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.entropywins.wtf\/blog\/wp-content\/uploads\/2016\/11\/lloc-per-global.png?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.entropywins.wtf\/blog\/wp-content\/uploads\/2016\/11\/lloc-per-global.png?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":2877,"url":"https:\/\/www.entropywins.wtf\/blog\/2022\/09\/21\/advice-for-junior-developers\/","url_meta":{"origin":1131,"position":5},"title":"Advice for junior developers","author":"Jeroen","date":"2022-09-21","format":false,"excerpt":"Over the 15+ years of my development career, I have learned several things that significantly increase my effectiveness. In this post, I share those learnings with you. Structure: Generic Advice -- Important context and motivation for the technical advice Technical Advice -- The main course Recommended Reading -- Links to\u2026","rel":"","context":"In "Programming"","block_context":{"text":"Programming","link":"https:\/\/www.entropywins.wtf\/blog\/category\/programming\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.entropywins.wtf\/blog\/wp-content\/uploads\/2022\/09\/code.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.entropywins.wtf\/blog\/wp-content\/uploads\/2022\/09\/code.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.entropywins.wtf\/blog\/wp-content\/uploads\/2022\/09\/code.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.entropywins.wtf\/blog\/wp-content\/uploads\/2022\/09\/code.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/www.entropywins.wtf\/blog\/wp-content\/uploads\/2022\/09\/code.jpg?resize=1050%2C600&ssl=1 3x"},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.entropywins.wtf\/blog\/wp-json\/wp\/v2\/posts\/1131","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.entropywins.wtf\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.entropywins.wtf\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.entropywins.wtf\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.entropywins.wtf\/blog\/wp-json\/wp\/v2\/comments?post=1131"}],"version-history":[{"count":5,"href":"https:\/\/www.entropywins.wtf\/blog\/wp-json\/wp\/v2\/posts\/1131\/revisions"}],"predecessor-version":[{"id":2355,"href":"https:\/\/www.entropywins.wtf\/blog\/wp-json\/wp\/v2\/posts\/1131\/revisions\/2355"}],"wp:attachment":[{"href":"https:\/\/www.entropywins.wtf\/blog\/wp-json\/wp\/v2\/media?parent=1131"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.entropywins.wtf\/blog\/wp-json\/wp\/v2\/categories?post=1131"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.entropywins.wtf\/blog\/wp-json\/wp\/v2\/tags?post=1131"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}