--- title: New JavaScript Set methods | daily.dev description: New JavaScript Set methods such as intersection, union, difference, symmetricDifference, isSubsetOf, isSupersetOf, and isDisjointFrom have become available... canonical: https://daily.dev/posts/new-javascript-set-methods-jbhmchtna twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: New JavaScript Set methods | daily.dev og:description: New JavaScript Set methods such as intersection, union, difference, symmetricDifference, isSubsetOf, isSupersetOf, and isDisjointFrom have become available... og:url: https://daily.dev/posts/new-javascript-set-methods-jbhmchtna og:image: https://api.daily.dev/og/posts/JBHMcHTna.png og:image:alt: New JavaScript Set methods og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # New JavaScript Set methods **[MDN Blog](https://daily.dev/sources/mdnblog)** · 2 min read · 762 upvotes · 27 comments ## Summary New JavaScript Set methods such as intersection, union, difference, symmetricDifference, isSubsetOf, isSupersetOf, and isDisjointFrom have become available across most major browser engines without the need for polyfills. These methods facilitate various set operations, making it easier to perform operations like finding common elements, combining sets, and checking subset or superset relationships. Sets in JavaScript offer advantages for unique collections and performance improvements over arrays when dealing with larger datasets. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Community discussion Top comments from developers on daily.dev. **@growupanand** · 4 upvotes > This is very useful, I always wonder why I should use Set over Array, and these methods answer. **@sur\_\_** · 3 upvotes > woo hoo, thanks for sharing 🙌 really helpful > here is a TLDR: > > # New Set Methods > > JavaScript’s Set object now includes new methods available in major browsers like Firefox 127, eliminating the need for polyfills1. > > ## Set Advantages > > Sets ensure unique values and offer performance benefits over arrays, especially with large data sets. > > ## Method Examples > > The article provides examples of union, intersection, symmetric difference, and set difference methods for combining or comparing sets. > > ## Boolean Operations > > New methods like `isSubsetOf`, `isSupersetOf`, and `isDisjointFrom` perform... **@lbsudo** · 1 upvotes > I know a lot of people hate on JS but idk why it gets better every year **@mister\_shadrack** · 0 upvotes > Thanks for sharing. You now see clearly when to use Set over an array. **@dushyantdotdev** · 0 upvotes > Thanks for the sharing ## Similar posts on daily.dev - [Don’t just attend KubeCon \+ CloudNativeCon, Merge Forward your experience\!](https://daily.dev/posts/don-t-just-attend-kubecon-cloudnativecon-merge-forward-your-experience--l0rpp73x8) · CNCF · 1 upvotes · 0 comments - [Announcing H2 2026 KCDs](https://daily.dev/posts/announcing-h2-2026-kcds-m96goajm1) · CNCF · 1 upvotes · 0 comments - [Two months of Open Community Groups](https://daily.dev/posts/two-months-of-open-community-groups-asf52zhbs) · CNCF · 0 upvotes · 0 comments - [CNCF Unveils Schedule for KubeCon \+ CloudNativeCon Europe 2026](https://daily.dev/posts/cncf-unveils-schedule-for-kubecon-cloudnativecon-europe-2026-ikhcoa5cb) · CNCF · 2 upvotes · 0 comments - [CNCF Debuts KubeCon \+ CloudNativeCon Japan 2026 Schedule](https://daily.dev/posts/cncf-debuts-kubecon-cloudnativecon-japan-2026-schedule-xp5pyudub) · CNCF · 1 upvotes · 0 comments --- Tags: [#webdev](https://daily.dev/tags/webdev), [#javascript](https://daily.dev/tags/javascript), [#browsers](https://daily.dev/tags/browsers) [View this post on daily.dev](https://daily.dev/posts/new-javascript-set-methods-jbhmchtna) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} 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127, eliminating the need for polyfills1.\n\nSet Advantages\n\nSets ensure unique values and offer performance benefits over arrays, especially with large data sets.\n\nMethod Examples\n\nThe article provides examples of union, intersection, symmetric difference, and set difference methods for combining or comparing sets.\n\nBoolean Operations\n\nNew methods like isSubsetOf, isSupersetOf, and isDisjointFrom perform logical checks and return Boolean values.","datePublished":"2024-06-27T11:36:42.995Z","url":"https://daily.dev/posts/JBHMcHTna#c-Rq5G0W0ZE","author":{"@type":"Person","name":"sur","url":"https://daily.dev/sur__","image":"https://media.daily.dev/image/upload/s--bjMknJQF--/f_auto/v1718758407/avatars/avatar_4g43kX3nFeykVFcjzqaWv"},"interactionStatistic":{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":3}},{"@type":"Comment","text":"I know a lot of people hate on JS but idk why it gets better every year","datePublished":"2024-06-26T19:12:55.110Z","url":"https://daily.dev/posts/JBHMcHTna#c-DuTSa84cg","author":{"@type":"Person","name":"Lawrence Brown","url":"https://daily.dev/lbsudo","image":"https://media.daily.dev/image/upload/s--3UpGLA5v--/f_auto/v1716964837/avatars/avatar_cAeoiL0VUxXQhEGePluN4"},"interactionStatistic":{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":1}},{"@type":"Comment","text":"Thanks for sharing. You now see clearly when to use Set over an array.","datePublished":"2024-06-27T12:11:10.441Z","url":"https://daily.dev/posts/JBHMcHTna#c-iTU7oKy99","author":{"@type":"Person","name":"Shadrack Ankomahene","url":"https://daily.dev/mister_shadrack","image":"https://avatars.githubusercontent.com/u/40831389?v=4"}},{"@type":"Comment","text":"Thanks for the sharing","datePublished":"2024-06-28T08:13:19.872Z","url":"https://daily.dev/posts/JBHMcHTna#c-LSIM6pPbp","author":{"@type":"Person","name":"Dushyant","url":"https://daily.dev/dushyantdotdev","image":"https://lh3.googleusercontent.com/a/ACg8ocKEqEHEGSx2gMm2azR6UGfjETFZRQUEgwbVFRwv-sPy4rky80Ng=s96-c"}}]} ```