{"id":3502,"date":"2022-06-21T14:00:00","date_gmt":"2022-06-21T14:00:00","guid":{"rendered":"http:\/\/the-codest.localhost\/blog\/functional-programming-in-javascript-part-3-functor-monad-maybe\/"},"modified":"2026-03-11T05:59:01","modified_gmt":"2026-03-11T05:59:01","slug":"funkcinis-programavimas-javascript-3-dalis-funktorius-monada-gal","status":"publish","type":"post","link":"https:\/\/thecodest.co\/lt\/blog\/functional-programming-in-javascript-part-3-functor-monad-maybe\/","title":{"rendered":"Funkcinis programavimas JavaScript 3 dalis - Funktorius ir monada Galb\u016bt"},"content":{"rendered":"<h2 class=\"wp-block-heading\">\u012evadas<\/h2>\n\n\n\n<p>Da\u017enai sunku i\u0161laikyti nemodifikuojam\u0105. \u012evyniojimo modelis <a href=\"https:\/\/thecodest.co\/lt\/blog\/app-data-collection-security-risks-value-and-types-explored\/\">duomenys<\/a> \u012f konteiner\u012f. Jis apsaugo vertybes, kad su jomis b\u016bt\u0173 galima saugiai dirbti ir nesukelti \u0161alutinio poveikio.<\/p>\n\n\n\n<p>Jei esate \u010dia nauji, b\u016btinai per\u017ei\u016br\u0117kite mano paskutines 2 dalis apie funkcin\u012f programavim\u0105 <a href=\"https:\/\/thecodest.co\/lt\/blog\/vibrant-upturn-charting-the-resolute-rise-of-swedish-firms\/\">The Codest<\/a> tinklara\u0161tis apie:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/thecodest.co\/blog\/power-of-functional-programming-in-javascript-part-1-introduction\">1 dalis - \u012evadas<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/thecodest.co\/blog\/power-of-functional-programming-in-javascript-part-2-combinators\">2 dalis - Kombinatoriai<\/a><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Funktorius<\/h2>\n\n\n\n<p>Jame n\u0117ra sud\u0117tingos logikos. Pagrindin\u0117 jo u\u017eduotis - apgaubti kontekst\u0105 ir atlikti su juo i\u0161 i\u0161or\u0117s gaunamas funkcijas. Kiekvien\u0105 kart\u0105 pasikeitus vertei, perpakuojamas ir gr\u0105\u017einamas naujas konteinerio egzempliorius. Kvie\u010diant <b>\u017eem\u0117lapis<\/b> metod\u0105, kuris atlieka tam tikr\u0105 veiksm\u0105, jis gr\u0105\u017eina nauj\u0105 konteinerio egzempliori\u0173 su perduotos funkcijos gr\u0105\u017einta verte, i\u0161laikant nekei\u010diamumo princip\u0105.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Deklaracija<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"javascript\" class=\"language-javascript\"><code> const Functor = value =&gt; ({ {\n     map: fn =&gt; Functor(fn(value)),\n     chain: fn =&gt; fn(value),\n     of: () =&gt; value\n });<\/code><\/code><\/pre>\n\n\n\n<p><b>\u017eem\u0117lapis<\/b> - naudinga, kai norite pakeisti konteinerio reik\u0161m\u0117s b\u016bsen\u0105, bet dar nenorite jos gr\u0105\u017einti.<\/p>\n\n\n\n<p><b>grandin\u0117<\/b> - naudojamas, jei norite perduoti reik\u0161m\u0119 funkcijai nekeisdami konteinerio b\u016bsenos. Paprastai funkcijos pabaigoje <b>\u017eem\u0117lapis<\/b> skambu\u010diai.<\/p>\n\n\n\n<p><b>i\u0161<\/b> - gr\u0105\u017einti dabartin\u0119 vert\u0119<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Imperatyvus pavyzdys<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"javascript\" class=\"language-javascript\">const randomInt = (max) =&gt; Math.floor(Math.random() * (max + 1))\n\nconst randomNumber = randomInt(200) \/\/ gr\u0105\u017einamas skai\u010dius nuo 0 iki 200\n\ndecrease(randomNumber) \/\/ gr\u0105\u017einamas skai\u010dius (nuo 0 iki 200) - 1<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">Deklaratyvinis pavyzdys<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"javascript\" class=\"language-javascript\">const randomIntWrapper = (max) =&gt;\nFunctor(max)\n.map(increase) \/\/ max + 1\n.map(multiplyBy(Math.random())) \/\/ Math.random() * (max + 1)\n.map(Math.floor) \/\/ Math.floor(Math.random() * (max + 1))\n\nconst randomNumber = randomIntWrapper(200)\n\nrandomNumber.of() \/\/ gr\u0105\u017einamas skai\u010dius nuo 0 iki 200\nrandomNumber.chain(decrease) \/\/ gr\u0105\u017eina (skai\u010di\u0173 nuo 0 iki 200) - 1<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">Monada<\/h2>\n\n\n\n<p>Kartais, be funkcij\u0173, sukelian\u010di\u0173 nauj\u0105 reik\u0161m\u0117s b\u016bsen\u0105, reikia papildomos logikos, pasl\u0117ptos konteineryje. \u010cia praver\u010dia monada, nes ji yra pl\u0117tinys <b>funktorius<\/b>. Pavyzd\u017eiui, jis gali nuspr\u0119sti, kas tur\u0117t\u0173 \u012fvykti, kai reik\u0161m\u0117 \u012fgyja tam tikr\u0105 vert\u0119, arba kokiu keliu turi b\u016bti atliekami kiti veiksmai.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Monada Galb\u016bt<\/h2>\n\n\n\n<p>Monada galb\u016bt i\u0161sprend\u017eia ver\u010di\u0173, kurios gr\u0105\u017eina ne true, problem\u0105. Kai taip atsitinka, v\u0117lesni <b>\u017eem\u0117lapis<\/b> skambu\u010diai ignoruojami, ta\u010diau galima gr\u0105\u017einti alternatyv\u0173 skambinant \u012f <b>getOr<\/b> metodas. Tai leid\u017eia i\u0161vengti operatori\u0173 if \/ else, kurie populiar\u016bs <b>imperatyvas<\/b> programavimas. \u0160i\u0105 monad\u0105 sudaro trys konteineriai:<\/p>\n\n\n\n<p><b>Nieko<\/b> - paleid\u017eiamas, kai \u012f konteiner\u012f patenka reik\u0161m\u0117, kuri n\u0117ra true, arba <strong>filtras<\/strong> metodas gr\u0105\u017eina false. Jis naudojamas funkcijos vykdymui imituoti. Tai rei\u0161kia, kad \u0161is konteineris gauna funkcij\u0105, bet jos nevykdo.<\/p>\n\n\n\n<p><b>Tiesiog<\/b> - tai yra pagrindinis konteineris, kuris atlieka visas funkcijas, ta\u010diau jei reik\u0161m\u0117 pasikei\u010dia \u012f klaiding\u0105 reik\u0161m\u0119 arba <b>filtras<\/b> metodas gr\u0105\u017eina false, jis perduos j\u012f \u012f <b>Nieko<\/b> konteineris.<\/p>\n\n\n\n<p><b>Galb\u016bt<\/b> - Paimu pradin\u0119 vert\u0119 ir nusprend\u017eiu, kok\u012f konteiner\u012f i\u0161kviesti prad\u017eioje.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Deklaracija<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"javascript\" class=\"language-javascript\">const Just = value =&gt; ({\nmap: fn =&gt; Maybe(fn(value)),\nchain: fn =&gt; fn(value),\nof: () =&gt; value,\ngetOr: () =&gt; value,\nfilter: fn =&gt; fn(value) ? Just(value) : Nothing(),\ntype: \"just\n});\n\nconst Nothing = () =&gt; ({\nmap: fn =&gt; Nothing(),\nchain: fn =&gt; fn(),\nof: () =&gt; Nothing(),\ngetOr: substitute =&gt; substitute,\nfilter: () =&gt; Nothing(),\ntype: \"nothing\n});\n\nconst Maybe = value =&gt;\nvalue === null || value === undefined || value.type === 'nothing'\n? Nothing()\n: Just(value)<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"\/app\/uploads\/2024\/05\/table.png\" alt=\"lentel\u0117s metodai funktorius \" title=\"lentel\u0117s funktorius \"\/><\/figure>\n\n\n\n<p>Dabar sukurkime ankstesn\u012f pavyzd\u012f apie s\u0105lyg\u0105. Jei max yra didesnis u\u017e nul\u012f, bus vykdoma funkcija. Prie\u0161ingu atveju ji gr\u0105\u017eins 0.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Imperatyvus pavyzdys<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"javascript\" class=\"language-javascript\">const randomInt = (max) =&gt; {\nif(max &gt; 0) {\nreturn Math.floor(Math.random() * (max + 1))\n} else {\nreturn 0\n}\n}\n\nconst bookMiddlePage = 200\n\nconst randomPage = randomInt(10) || bookMiddlePage \/\/ gr\u0105\u017eina atsitiktin\u012f variant\u0105\nconst randomPage = randomInt(-10) || bookMiddlePage \/\/ gr\u0105\u017eina 200<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">Deklaratyvinis pavyzdys<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"javascript\" class=\"language-javascript\">const randomIntWrapper = (max) =&gt;\nMaybe(max)\n.filter(max =&gt; max &gt; 0) \/\/ reik\u0161m\u0117 false ignoruoja tolesnius i\u0161kvietimus\n.map(padidinti)\n.map(multiplyBy(Math.random()))\n.map(Math.floor)\n\nconst bookMiddlePage = 200\n\n\/\/ Tiesiog konteineris\nconst randomPage = randomIntWrapper(10).getOr(bookMiddlePage) \/\/ gr\u0105\u017eina atsitiktin\u012f skai\u010di\u0173\n\/\/ Nieko konteineris\nconst randomPage = randomIntWrapper(-10).getOr(bookMiddlePage) \/\/ gr\u0105\u017eina 200<\/code><\/pre>\n\n\n\n<p><br><a href=\"https:\/\/thecodest.co\/contact\"><img decoding=\"async\" src=\"\/app\/uploads\/2024\/05\/interested_in_cooperation_.png\" alt=\"bendradarbiavimo v\u0117liava\"><\/a><\/p>","protected":false},"excerpt":{"rendered":"<p>Per\u017ei\u016br\u0117kite tre\u010di\u0105j\u0105 m\u016bs\u0173 straipsni\u0173 ciklo \"Funkcinio programavimo galia JavaScript\" dal\u012f. \u0160\u012f kart\u0105 m\u016bs\u0173 JavaScript ekspertas paai\u0161kina daugiau apie Functor ir Monad Maybe.<\/p>","protected":false},"author":2,"featured_media":3503,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"categories":[8],"tags":[],"class_list":["post-3502","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-software-development"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v27.3 (Yoast SEO v27.3) - https:\/\/yoast.com\/product\/yoast-seo-premium-wordpress\/ -->\n<title>Functional programming in JavaScript Part 3 - Functor &amp; Monad Maybe - The Codest<\/title>\n<meta name=\"description\" content=\"Check the third part of our Power of functional programming in JavaScript article series. This time our JavaScript expert explains more about Functor and Monad Maybe.\" \/>\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\/lt\/tinklarastis\/funkcinis-programavimas-javascript-3-dalis-funktorius-monada-gal\/\" \/>\n<meta property=\"og:locale\" content=\"lt_LT\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Functional programming in JavaScript Part 3 - Functor &amp; Monad Maybe\" \/>\n<meta property=\"og:description\" content=\"Check the third part of our Power of functional programming in JavaScript article series. This time our JavaScript expert explains more about Functor and Monad Maybe.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/thecodest.co\/lt\/tinklarastis\/funkcinis-programavimas-javascript-3-dalis-funktorius-monada-gal\/\" \/>\n<meta property=\"og:site_name\" content=\"The Codest\" \/>\n<meta property=\"article:published_time\" content=\"2022-06-21T14:00:00+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-03-11T05:59:01+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/thecodest.co\/app\/uploads\/2024\/05\/power_of_functional_programming_in_javascript_part_3_-_functor_-_monad_maybe.png\" \/>\n\t<meta property=\"og:image:width\" content=\"960\" \/>\n\t<meta property=\"og:image:height\" content=\"540\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"author\" content=\"thecodest\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"thecodest\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"3 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/thecodest.co\\\/blog\\\/functional-programming-in-javascript-part-3-functor-monad-maybe\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/thecodest.co\\\/blog\\\/functional-programming-in-javascript-part-3-functor-monad-maybe\\\/\"},\"author\":{\"name\":\"thecodest\",\"@id\":\"https:\\\/\\\/thecodest.co\\\/#\\\/schema\\\/person\\\/7e3fe41dfa4f4e41a7baad4c6e0d4f76\"},\"headline\":\"Functional programming in JavaScript Part 3 &#8211; Functor &#038; Monad Maybe\",\"datePublished\":\"2022-06-21T14:00:00+00:00\",\"dateModified\":\"2026-03-11T05:59:01+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/thecodest.co\\\/blog\\\/functional-programming-in-javascript-part-3-functor-monad-maybe\\\/\"},\"wordCount\":437,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\\\/\\\/thecodest.co\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/thecodest.co\\\/blog\\\/functional-programming-in-javascript-part-3-functor-monad-maybe\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/thecodest.co\\\/app\\\/uploads\\\/2024\\\/05\\\/power_of_functional_programming_in_javascript_part_3_-_functor_-_monad_maybe.png\",\"articleSection\":[\"Software Development\"],\"inLanguage\":\"lt-LT\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/thecodest.co\\\/blog\\\/functional-programming-in-javascript-part-3-functor-monad-maybe\\\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/thecodest.co\\\/blog\\\/functional-programming-in-javascript-part-3-functor-monad-maybe\\\/\",\"url\":\"https:\\\/\\\/thecodest.co\\\/blog\\\/functional-programming-in-javascript-part-3-functor-monad-maybe\\\/\",\"name\":\"Functional programming in JavaScript Part 3 - Functor & Monad Maybe - The Codest\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/thecodest.co\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/thecodest.co\\\/blog\\\/functional-programming-in-javascript-part-3-functor-monad-maybe\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/thecodest.co\\\/blog\\\/functional-programming-in-javascript-part-3-functor-monad-maybe\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/thecodest.co\\\/app\\\/uploads\\\/2024\\\/05\\\/power_of_functional_programming_in_javascript_part_3_-_functor_-_monad_maybe.png\",\"datePublished\":\"2022-06-21T14:00:00+00:00\",\"dateModified\":\"2026-03-11T05:59:01+00:00\",\"description\":\"Check the third part of our Power of functional programming in JavaScript article series. This time our JavaScript expert explains more about Functor and Monad Maybe.\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/thecodest.co\\\/blog\\\/functional-programming-in-javascript-part-3-functor-monad-maybe\\\/#breadcrumb\"},\"inLanguage\":\"lt-LT\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/thecodest.co\\\/blog\\\/functional-programming-in-javascript-part-3-functor-monad-maybe\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"lt-LT\",\"@id\":\"https:\\\/\\\/thecodest.co\\\/blog\\\/functional-programming-in-javascript-part-3-functor-monad-maybe\\\/#primaryimage\",\"url\":\"https:\\\/\\\/thecodest.co\\\/app\\\/uploads\\\/2024\\\/05\\\/power_of_functional_programming_in_javascript_part_3_-_functor_-_monad_maybe.png\",\"contentUrl\":\"https:\\\/\\\/thecodest.co\\\/app\\\/uploads\\\/2024\\\/05\\\/power_of_functional_programming_in_javascript_part_3_-_functor_-_monad_maybe.png\",\"width\":960,\"height\":540},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/thecodest.co\\\/blog\\\/functional-programming-in-javascript-part-3-functor-monad-maybe\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/thecodest.co\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Functional programming in JavaScript Part 3 &#8211; Functor &#038; Monad Maybe\"}]},{\"@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\":\"lt-LT\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/thecodest.co\\\/#organization\",\"name\":\"The Codest\",\"url\":\"https:\\\/\\\/thecodest.co\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"lt-LT\",\"@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\"]},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/thecodest.co\\\/#\\\/schema\\\/person\\\/7e3fe41dfa4f4e41a7baad4c6e0d4f76\",\"name\":\"thecodest\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"lt-LT\",\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/5dbfe6a1e8c86e432e8812759e34e6fe82ebac75119ae3237a6c1311fa19caf4?s=96&d=mm&r=g\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/5dbfe6a1e8c86e432e8812759e34e6fe82ebac75119ae3237a6c1311fa19caf4?s=96&d=mm&r=g\",\"contentUrl\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/5dbfe6a1e8c86e432e8812759e34e6fe82ebac75119ae3237a6c1311fa19caf4?s=96&d=mm&r=g\",\"caption\":\"thecodest\"},\"url\":\"https:\\\/\\\/thecodest.co\\\/lt\\\/author\\\/thecodest\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"Funkcinis programavimas JavaScript 3 dalis - Funktorius ir monada Galb\u016bt - The Codest","description":"Per\u017ei\u016br\u0117kite tre\u010di\u0105j\u0105 m\u016bs\u0173 straipsni\u0173 ciklo \"Funkcinio programavimo galia JavaScript\" dal\u012f. \u0160\u012f kart\u0105 m\u016bs\u0173 JavaScript ekspertas paai\u0161kina daugiau apie Functor ir Monad Maybe.","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\/lt\/tinklarastis\/funkcinis-programavimas-javascript-3-dalis-funktorius-monada-gal\/","og_locale":"lt_LT","og_type":"article","og_title":"Functional programming in JavaScript Part 3 - Functor & Monad Maybe","og_description":"Check the third part of our Power of functional programming in JavaScript article series. This time our JavaScript expert explains more about Functor and Monad Maybe.","og_url":"https:\/\/thecodest.co\/lt\/tinklarastis\/funkcinis-programavimas-javascript-3-dalis-funktorius-monada-gal\/","og_site_name":"The Codest","article_published_time":"2022-06-21T14:00:00+00:00","article_modified_time":"2026-03-11T05:59:01+00:00","og_image":[{"width":960,"height":540,"url":"https:\/\/thecodest.co\/app\/uploads\/2024\/05\/power_of_functional_programming_in_javascript_part_3_-_functor_-_monad_maybe.png","type":"image\/png"}],"author":"thecodest","twitter_card":"summary_large_image","twitter_misc":{"Written by":"thecodest","Est. reading time":"3 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/thecodest.co\/blog\/functional-programming-in-javascript-part-3-functor-monad-maybe\/#article","isPartOf":{"@id":"https:\/\/thecodest.co\/blog\/functional-programming-in-javascript-part-3-functor-monad-maybe\/"},"author":{"name":"thecodest","@id":"https:\/\/thecodest.co\/#\/schema\/person\/7e3fe41dfa4f4e41a7baad4c6e0d4f76"},"headline":"Functional programming in JavaScript Part 3 &#8211; Functor &#038; Monad Maybe","datePublished":"2022-06-21T14:00:00+00:00","dateModified":"2026-03-11T05:59:01+00:00","mainEntityOfPage":{"@id":"https:\/\/thecodest.co\/blog\/functional-programming-in-javascript-part-3-functor-monad-maybe\/"},"wordCount":437,"commentCount":0,"publisher":{"@id":"https:\/\/thecodest.co\/#organization"},"image":{"@id":"https:\/\/thecodest.co\/blog\/functional-programming-in-javascript-part-3-functor-monad-maybe\/#primaryimage"},"thumbnailUrl":"https:\/\/thecodest.co\/app\/uploads\/2024\/05\/power_of_functional_programming_in_javascript_part_3_-_functor_-_monad_maybe.png","articleSection":["Software Development"],"inLanguage":"lt-LT","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/thecodest.co\/blog\/functional-programming-in-javascript-part-3-functor-monad-maybe\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/thecodest.co\/blog\/functional-programming-in-javascript-part-3-functor-monad-maybe\/","url":"https:\/\/thecodest.co\/blog\/functional-programming-in-javascript-part-3-functor-monad-maybe\/","name":"Funkcinis programavimas JavaScript 3 dalis - Funktorius ir monada Galb\u016bt - The Codest","isPartOf":{"@id":"https:\/\/thecodest.co\/#website"},"primaryImageOfPage":{"@id":"https:\/\/thecodest.co\/blog\/functional-programming-in-javascript-part-3-functor-monad-maybe\/#primaryimage"},"image":{"@id":"https:\/\/thecodest.co\/blog\/functional-programming-in-javascript-part-3-functor-monad-maybe\/#primaryimage"},"thumbnailUrl":"https:\/\/thecodest.co\/app\/uploads\/2024\/05\/power_of_functional_programming_in_javascript_part_3_-_functor_-_monad_maybe.png","datePublished":"2022-06-21T14:00:00+00:00","dateModified":"2026-03-11T05:59:01+00:00","description":"Per\u017ei\u016br\u0117kite tre\u010di\u0105j\u0105 m\u016bs\u0173 straipsni\u0173 ciklo \"Funkcinio programavimo galia JavaScript\" dal\u012f. \u0160\u012f kart\u0105 m\u016bs\u0173 JavaScript ekspertas paai\u0161kina daugiau apie Functor ir Monad Maybe.","breadcrumb":{"@id":"https:\/\/thecodest.co\/blog\/functional-programming-in-javascript-part-3-functor-monad-maybe\/#breadcrumb"},"inLanguage":"lt-LT","potentialAction":[{"@type":"ReadAction","target":["https:\/\/thecodest.co\/blog\/functional-programming-in-javascript-part-3-functor-monad-maybe\/"]}]},{"@type":"ImageObject","inLanguage":"lt-LT","@id":"https:\/\/thecodest.co\/blog\/functional-programming-in-javascript-part-3-functor-monad-maybe\/#primaryimage","url":"https:\/\/thecodest.co\/app\/uploads\/2024\/05\/power_of_functional_programming_in_javascript_part_3_-_functor_-_monad_maybe.png","contentUrl":"https:\/\/thecodest.co\/app\/uploads\/2024\/05\/power_of_functional_programming_in_javascript_part_3_-_functor_-_monad_maybe.png","width":960,"height":540},{"@type":"BreadcrumbList","@id":"https:\/\/thecodest.co\/blog\/functional-programming-in-javascript-part-3-functor-monad-maybe\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/thecodest.co\/"},{"@type":"ListItem","position":2,"name":"Functional programming in JavaScript Part 3 &#8211; Functor &#038; Monad Maybe"}]},{"@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":"lt-LT"},{"@type":"Organization","@id":"https:\/\/thecodest.co\/#organization","name":"The Codest","url":"https:\/\/thecodest.co\/","logo":{"@type":"ImageObject","inLanguage":"lt-LT","@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"]},{"@type":"Person","@id":"https:\/\/thecodest.co\/#\/schema\/person\/7e3fe41dfa4f4e41a7baad4c6e0d4f76","name":"thecodest","image":{"@type":"ImageObject","inLanguage":"lt-LT","@id":"https:\/\/secure.gravatar.com\/avatar\/5dbfe6a1e8c86e432e8812759e34e6fe82ebac75119ae3237a6c1311fa19caf4?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/5dbfe6a1e8c86e432e8812759e34e6fe82ebac75119ae3237a6c1311fa19caf4?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/5dbfe6a1e8c86e432e8812759e34e6fe82ebac75119ae3237a6c1311fa19caf4?s=96&d=mm&r=g","caption":"thecodest"},"url":"https:\/\/thecodest.co\/lt\/author\/thecodest\/"}]}},"_links":{"self":[{"href":"https:\/\/thecodest.co\/lt\/wp-json\/wp\/v2\/posts\/3502","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/thecodest.co\/lt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/thecodest.co\/lt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/thecodest.co\/lt\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/thecodest.co\/lt\/wp-json\/wp\/v2\/comments?post=3502"}],"version-history":[{"count":8,"href":"https:\/\/thecodest.co\/lt\/wp-json\/wp\/v2\/posts\/3502\/revisions"}],"predecessor-version":[{"id":8386,"href":"https:\/\/thecodest.co\/lt\/wp-json\/wp\/v2\/posts\/3502\/revisions\/8386"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/thecodest.co\/lt\/wp-json\/wp\/v2\/media\/3503"}],"wp:attachment":[{"href":"https:\/\/thecodest.co\/lt\/wp-json\/wp\/v2\/media?parent=3502"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/thecodest.co\/lt\/wp-json\/wp\/v2\/categories?post=3502"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/thecodest.co\/lt\/wp-json\/wp\/v2\/tags?post=3502"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}