{"id":6643,"date":"2026-04-13T11:50:53","date_gmt":"2026-04-13T11:50:53","guid":{"rendered":"http:\/\/the-codest.localhost\/dictionary\/react\/"},"modified":"2026-04-13T11:50:53","modified_gmt":"2026-04-13T11:50:53","slug":"react","status":"publish","type":"dictionary","link":"https:\/\/thecodest.co\/is\/dictionary\/react\/","title":{"rendered":"React"},"content":{"rendered":"

React: Alhli\u00f0a skilgreining<\/h1>\n

React<\/a> er vins\u00e6ll opinn hugb\u00fana\u00f0ur JavaScript<\/a> B\u00f3kasafn sem nota\u00f0 er til a\u00f0 b\u00faa til notendavi\u00f0m\u00f3t (UIs). \u00dea\u00f0 var \u00fer\u00f3a\u00f0 af Facebook og er n\u00fa vi\u00f0haldi\u00f0 af samf\u00e9lagi forritara. React er \u00feekkt fyrir h\u00e6fileika sinn til a\u00f0 b\u00faa til d\u00fdnam\u00edsk og vi\u00f0brag\u00f0sflj\u00f3tleg notendavi\u00f0m\u00f3t me\u00f0 l\u00e1gmarks k\u00f3\u00f0un. \u00dea\u00f0 er miki\u00f0 nota\u00f0 til a\u00f0 byggja vefur<\/a> forrit, fars\u00edmaforrit og jafnvel skj\u00e1bor\u00f0sforrit.<\/p>\n

React byggir \u00e1 hugmyndinni um \u00edhluti. \u00cdhlutur er sj\u00e1lfst\u00e6tt blokk af k\u00f3\u00f0i<\/a> sem h\u00e6gt er a\u00f0 endurn\u00fdta \u00ed gegnum forriti\u00f0. \u00dea\u00f0 m\u00e1 l\u00edta \u00e1 \u00fea\u00f0 sem byggingareiningu sem h\u00e6gt er a\u00f0 sameina vi\u00f0 a\u00f0rar einingar til a\u00f0 b\u00faa til fullkominn notendavi\u00f0m\u00f3t. React \u00edhlutir<\/a> eru bygg\u00f0 me\u00f0 bl\u00f6ndu af HTML-l\u00edkri setningafr\u00e6\u00f0i sem kallast JSX og JavaScript.<\/p>\n

Ein af lykilatri\u00f0um React er s\u00fdndar-DOM (Document Object Model). S\u00fdndar-DOM er l\u00e9tt yfirlitsl\u00fdsing yfir raunverulega DOM. \u00deegar breyting er ger\u00f0 \u00e1 \u00edhlut uppf\u00e6rir React s\u00fdndar-DOM \u00ed sta\u00f0 raunverulegs DOM. \u00deetta gerir React kleift a\u00f0 \u00e1kvar\u00f0a \u00e1 skilvirkan h\u00e1tt hva\u00f0a breytingar \u00fearf a\u00f0 gera \u00e1 notendavi\u00f0m\u00f3tinu og uppf\u00e6ra a\u00f0eins \u00fe\u00e6r hluta \u00feess. \u00deetta lei\u00f0ir til hra\u00f0ari birtingar og m\u00fdkri notendaupplifunar.<\/p>\n

React er einnig \u00feekkt fyrir sinn einstefnu g\u00f6gn<\/a> Fl\u00e6\u00f0i. \u00cd React fl\u00e6\u00f0ir g\u00f6gnin \u00ed eina \u00e1tt, fr\u00e1 foreldrisamhlutum til barnsamhluta. \u00deetta au\u00f0veldar stj\u00f3rnun gagna og tryggir a\u00f0 notendavi\u00f0m\u00f3ti\u00f0 s\u00e9 alltaf uppf\u00e6rt.<\/p>\n

React er mj\u00f6g s\u00e9rsni\u00f0inn og h\u00e6gt er a\u00f0 nota hann me\u00f0 \u00f6\u00f0rum b\u00f3kas\u00f6fnum og rammasetningum. Hann m\u00e1 nota me\u00f0 vins\u00e6lum front-end rammasetningum, svo sem Einn tveggja p\u00f3sts 60 tonn<\/a> og Vue<\/a>.js. \u00dea\u00f0 er einnig h\u00e6gt a\u00f0 nota me\u00f0 bakendaumgj\u00f6r\u00f0um eins og Node.js<\/a>.<\/p>\n

React hefur st\u00f3rt og virkt samf\u00e9lag forritara sem leggja sitt af m\u00f6rkum til \u00fer\u00f3unar \u00feess og veita \u00f6\u00f0rum forriturum stu\u00f0ning. Fj\u00f6lmargar au\u00f0lindir eru tilt\u00e6kar til a\u00f0 l\u00e6ra React, \u00fear \u00e1 me\u00f0al skj\u00f6l, kennslulei\u00f0beiningar og netn\u00e1mskei\u00f0.<\/p>\n

A\u00f0 lokum er React \u00f6flug og sveigjanleg JavaScript-b\u00f3kasafn sem er nota\u00f0 til a\u00f0 byggja upp d\u00fdnam\u00edsk og vi\u00f0brag\u00f0sflj\u00f3tleg notendavi\u00f0m\u00f3t. \u00de\u00e1ttabundin uppbygging, s\u00fdndar-DOM og einsstefnu gagnastraumur gera \u00fea\u00f0 a\u00f0 kj\u00f6rnum vali til a\u00f0 byggja fl\u00f3kin forrit. Vins\u00e6ldir \u00feess og virkt samf\u00e9lag gera \u00fea\u00f0 a\u00f0 ver\u00f0m\u00e6tu t\u00e6ki fyrir hvern forritara sem vill byggja n\u00fat\u00edmaleg vefforrit.<\/p>","protected":false},"excerpt":{"rendered":"

Kynntu \u00fe\u00e9r React, vins\u00e6la opinn hugb\u00fana\u00f0ar-b\u00f3kasafni\u00f0 JavaScript sem er nota\u00f0 til a\u00f0 byggja upp d\u00fdnam\u00edsk og vi\u00f0brag\u00f0sflj\u00f3tleg notendavi\u00f0m\u00f3t me\u00f0 l\u00e1gmarks k\u00f3\u00f0un.<\/p>","protected":false},"template":"","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"class_list":["post-6643","dictionary","type-dictionary","status-publish","hentry"],"acf":[],"yoast_head":"\nReact - The Codest<\/title>\n<meta name=\"description\" content=\"Learn about React, the popular open-source JavaScript library used for building dynamic and responsive user interfaces with minimal coding.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/thecodest.co\/is\/ordabok\/react\/\" \/>\n<meta property=\"og:locale\" content=\"is_IS\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"React\" \/>\n<meta property=\"og:description\" content=\"Learn about React, the popular open-source JavaScript library used for building dynamic and responsive user interfaces with minimal coding.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/thecodest.co\/is\/ordabok\/react\/\" \/>\n<meta property=\"og:site_name\" content=\"The Codest\" \/>\n<meta property=\"og:image\" content=\"https:\/\/thecodest.co\/app\/uploads\/2024\/06\/cover-image.png\" \/>\n\t<meta property=\"og:image:width\" content=\"1200\" \/>\n\t<meta property=\"og:image:height\" content=\"675\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"2 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/thecodest.co\\\/dictionary\\\/react\\\/\",\"url\":\"https:\\\/\\\/thecodest.co\\\/dictionary\\\/react\\\/\",\"name\":\"React - The Codest\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/thecodest.co\\\/#website\"},\"datePublished\":\"2026-04-13T11:50:53+00:00\",\"description\":\"Learn about React, the popular open-source JavaScript library used for building dynamic and responsive user interfaces with minimal coding.\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/thecodest.co\\\/dictionary\\\/react\\\/#breadcrumb\"},\"inLanguage\":\"is\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/thecodest.co\\\/dictionary\\\/react\\\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/thecodest.co\\\/dictionary\\\/react\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/thecodest.co\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Dictionary\",\"item\":\"https:\\\/\\\/thecodest.co\\\/sv\\\/ordbok\\\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"React\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/thecodest.co\\\/#website\",\"url\":\"https:\\\/\\\/thecodest.co\\\/\",\"name\":\"The Codest\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\\\/\\\/thecodest.co\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/thecodest.co\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"is\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/thecodest.co\\\/#organization\",\"name\":\"The Codest\",\"url\":\"https:\\\/\\\/thecodest.co\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"is\",\"@id\":\"https:\\\/\\\/thecodest.co\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/thecodest.co\\\/app\\\/uploads\\\/2024\\\/03\\\/thecodest-logo.svg\",\"contentUrl\":\"https:\\\/\\\/thecodest.co\\\/app\\\/uploads\\\/2024\\\/03\\\/thecodest-logo.svg\",\"width\":144,\"height\":36,\"caption\":\"The Codest\"},\"image\":{\"@id\":\"https:\\\/\\\/thecodest.co\\\/#\\\/schema\\\/logo\\\/image\\\/\"},\"sameAs\":[\"https:\\\/\\\/pl.linkedin.com\\\/company\\\/codest\",\"https:\\\/\\\/clutch.co\\\/profile\\\/codest\"]}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"React - The Codest","description":"Kynntu \u00fe\u00e9r React, vins\u00e6la opinn hugb\u00fana\u00f0ar-b\u00f3kasafni\u00f0 JavaScript sem er nota\u00f0 til a\u00f0 byggja upp d\u00fdnam\u00edsk og vi\u00f0brag\u00f0sflj\u00f3tleg notendavi\u00f0m\u00f3t me\u00f0 l\u00e1gmarks k\u00f3\u00f0un.","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:\/\/thecodest.co\/is\/ordabok\/react\/","og_locale":"is_IS","og_type":"article","og_title":"React","og_description":"Learn about React, the popular open-source JavaScript library used for building dynamic and responsive user interfaces with minimal coding.","og_url":"https:\/\/thecodest.co\/is\/ordabok\/react\/","og_site_name":"The Codest","og_image":[{"width":1200,"height":675,"url":"https:\/\/thecodest.co\/app\/uploads\/2024\/06\/cover-image.png","type":"image\/png"}],"twitter_card":"summary_large_image","twitter_misc":{"Est. reading time":"2 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/thecodest.co\/dictionary\/react\/","url":"https:\/\/thecodest.co\/dictionary\/react\/","name":"React - The Codest","isPartOf":{"@id":"https:\/\/thecodest.co\/#website"},"datePublished":"2026-04-13T11:50:53+00:00","description":"Kynntu \u00fe\u00e9r React, vins\u00e6la opinn hugb\u00fana\u00f0ar-b\u00f3kasafni\u00f0 JavaScript sem er nota\u00f0 til a\u00f0 byggja upp d\u00fdnam\u00edsk og vi\u00f0brag\u00f0sflj\u00f3tleg notendavi\u00f0m\u00f3t me\u00f0 l\u00e1gmarks k\u00f3\u00f0un.","breadcrumb":{"@id":"https:\/\/thecodest.co\/dictionary\/react\/#breadcrumb"},"inLanguage":"is","potentialAction":[{"@type":"ReadAction","target":["https:\/\/thecodest.co\/dictionary\/react\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/thecodest.co\/dictionary\/react\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/thecodest.co\/"},{"@type":"ListItem","position":2,"name":"Dictionary","item":"https:\/\/thecodest.co\/sv\/ordbok\/"},{"@type":"ListItem","position":3,"name":"React"}]},{"@type":"WebSite","@id":"https:\/\/thecodest.co\/#website","url":"https:\/\/thecodest.co\/","name":"The Codest","description":"","publisher":{"@id":"https:\/\/thecodest.co\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/thecodest.co\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"is"},{"@type":"Organization","@id":"https:\/\/thecodest.co\/#organization","name":"The Codest","url":"https:\/\/thecodest.co\/","logo":{"@type":"ImageObject","inLanguage":"is","@id":"https:\/\/thecodest.co\/#\/schema\/logo\/image\/","url":"https:\/\/thecodest.co\/app\/uploads\/2024\/03\/thecodest-logo.svg","contentUrl":"https:\/\/thecodest.co\/app\/uploads\/2024\/03\/thecodest-logo.svg","width":144,"height":36,"caption":"The Codest"},"image":{"@id":"https:\/\/thecodest.co\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/pl.linkedin.com\/company\/codest","https:\/\/clutch.co\/profile\/codest"]}]}},"_links":{"self":[{"href":"https:\/\/thecodest.co\/is\/wp-json\/wp\/v2\/dictionary\/6643","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/thecodest.co\/is\/wp-json\/wp\/v2\/dictionary"}],"about":[{"href":"https:\/\/thecodest.co\/is\/wp-json\/wp\/v2\/types\/dictionary"}],"version-history":[{"count":1,"href":"https:\/\/thecodest.co\/is\/wp-json\/wp\/v2\/dictionary\/6643\/revisions"}],"predecessor-version":[{"id":10938,"href":"https:\/\/thecodest.co\/is\/wp-json\/wp\/v2\/dictionary\/6643\/revisions\/10938"}],"wp:attachment":[{"href":"https:\/\/thecodest.co\/is\/wp-json\/wp\/v2\/media?parent=6643"}],"curies":[{"name":"vp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}