{"id":1009,"date":"2019-12-27T16:26:04","date_gmt":"2019-12-27T16:26:04","guid":{"rendered":"https:\/\/golangbyexamples.com\/?p=1009"},"modified":"2019-12-27T16:28:54","modified_gmt":"2019-12-27T16:28:54","slug":"sort-custom-struct-collection-golang","status":"publish","type":"post","link":"https:\/\/golangbyexamples.com\/sort-custom-struct-collection-golang\/","title":{"rendered":"Sort a Custom Struct in Go (Golang)"},"content":{"rendered":"\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_17 counter-hierarchy counter-decimal ez-toc-light-blue\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" style=\"display: none;\"><i class=\"ez-toc-glyphicon ez-toc-icon-toggle\"><\/i><\/a><\/span><\/div>\n<nav><ul class=\"ez-toc-list ez-toc-list-level-1\"><li class=\"ez-toc-page-1 ez-toc-heading-level-1\"><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/golangbyexamples.com\/sort-custom-struct-collection-golang\/#Introduction\" title=\"Introduction\">Introduction<\/a><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-1\"><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/golangbyexamples.com\/sort-custom-struct-collection-golang\/#Full_Working_Code\" title=\"Full Working Code:\">Full Working Code:<\/a><\/li><\/ul><\/nav><\/div>\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Introduction\"><\/span><strong>Introduction<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<p class=\"has-medium-font-size\">GO has a <strong>sort<\/strong> package that provides utility primitives for the sorting of slices and user-defined types. Any collection can be sorted by the <strong>Sort<\/strong> function of <strong>sort<\/strong> package of GO it if implements the <strong>sort.Interface<\/strong>. <\/p>\n\n\n\n<p class=\"has-medium-font-size\">Below are the methods of sort.Interface<\/p>\n\n\n\n<p class=\"has-medium-font-size\"><a href=\"https:\/\/golang.org\/pkg\/sort\/#Interface\">https:\/\/golang.org\/pkg\/sort\/#Interface<\/a><\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">type Interface interface {\n    \/\/ Len is the number of elements in the collection.\n    Len() int\n    \n    \/\/ Less reports whether the element with\n    \/\/ index i should sort before the element with index j.\n    Less(i, j int) bool\n    \n    \/\/ Swap swaps the elements with indexes i and j.\n    Swap(i, j int)\n}<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">Let&#8217;s see a working example to illustrate how we can use <strong>sort.Interface<\/strong> to sort a user-defined struct. In below example <br><\/p>\n\n\n\n<ul class=\"has-medium-font-size wp-block-list\"><li>We created a custom struct called <strong>employee<\/strong> with <strong>name<\/strong> and <strong>salary<\/strong> in dollars as fields<\/li><\/ul>\n\n\n\n<ul class=\"has-medium-font-size wp-block-list\"><li>We have a <strong>employeeList<\/strong> which hold the list of <strong>employee<\/strong>.<\/li><\/ul>\n\n\n\n<ul class=\"has-medium-font-size wp-block-list\"><li><strong>employeeList<\/strong> implements the <strong>Len(), Less(), Swap()<\/strong> method hence it implements the <strong>sort.Interface<\/strong><\/li><\/ul>\n\n\n\n<ul class=\"has-medium-font-size wp-block-list\"><li>We sort the employee from highest salary to lowest salary. To sort employeeList we pass it to <strong>sort.Sort()<\/strong> function<\/li><\/ul>\n\n\n\n<p><\/p>\n\n\n\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Full_Working_Code\"><\/span><strong>Full Working Code:<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">package main\n\nimport (\n    \"fmt\"\n    \"sort\"\n)\n\ntype employee struct {\n    name   string\n    salary int\n}\n\ntype employeeList []employee\n\nfunc (e employeeList) Len() int {\n    return len(e)\n}\n\nfunc (e employeeList) Less(i, j int) bool {\n    return e[i].salary > e[j].salary\n}\n\nfunc (e employeeList) Swap(i, j int) {\n    e[i], e[j] = e[j], e[i]\n}\n\nfunc main() {\n    eList := []employee{\n        employee{name: \"John\", salary: 3000},\n        employee{name: \"Bill\", salary: 4000},\n        employee{name: \"Sam\", salary: 1000},\n    }\n    sort.Sort(employeeList(eList))\n    for _, employee := range eList {\n        fmt.Printf(\"Name: %s Salary %d\\n\", employee.name, employee.salary)\n    }\n}<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\"><strong>Output:<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">Name: Bill Salary 4000\nName: John Salary 3000\nName: Sam Salary 1000<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">To sort from lowest salary to highest salary we need to change the <strong>Less<\/strong> function with <strong>&#8216;>&#8217;<\/strong> sign<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">func (e employeeList) Less(i, j int) bool {\n    return e[i].salary > e[j].salary\n}<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">After changing it when we run the program then output will be:<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">Name: Sam Salary 1000\nName: John Salary 3000\nName: Bill Salary 4000<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Table of Contents IntroductionFull Working Code: Introduction GO has a sort package that provides utility primitives for the sorting of slices and user-defined types. Any collection can be sorted by the Sort&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":"","footnotes":"","jetpack_publicize_message":"","jetpack_is_tweetstorm":false},"categories":[1],"tags":[45,125,3,124],"class_list":["post-1009","post","type-post","status-publish","format-standard","hentry","category-tech","tag-array","tag-custom","tag-go","tag-structs"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v22.7 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Sort a Custom Struct in Go (Golang) - Welcome To Golang By Example<\/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:\/\/golangbyexamples.com\/sort-custom-struct-collection-golang\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Sort a Custom Struct in Go (Golang) - Welcome To Golang By Example\" \/>\n<meta property=\"og:description\" content=\"Table of Contents IntroductionFull Working Code: Introduction GO has a sort package that provides utility primitives for the sorting of slices and user-defined types. Any collection can be sorted by the Sort...\" \/>\n<meta property=\"og:url\" content=\"https:\/\/golangbyexamples.com\/sort-custom-struct-collection-golang\/\" \/>\n<meta property=\"og:site_name\" content=\"Welcome To Golang By Example\" \/>\n<meta property=\"article:published_time\" content=\"2019-12-27T16:26:04+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2019-12-27T16:28:54+00:00\" \/>\n<meta name=\"author\" content=\"admin\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"admin\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"2 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/golangbyexamples.com\/sort-custom-struct-collection-golang\/\",\"url\":\"https:\/\/golangbyexamples.com\/sort-custom-struct-collection-golang\/\",\"name\":\"Sort a Custom Struct in Go (Golang) - Welcome To Golang By Example\",\"isPartOf\":{\"@id\":\"https:\/\/golangbyexamples.com\/#website\"},\"datePublished\":\"2019-12-27T16:26:04+00:00\",\"dateModified\":\"2019-12-27T16:28:54+00:00\",\"author\":{\"@id\":\"https:\/\/golangbyexamples.com\/#\/schema\/person\/8833ea7638dafd763cb1db6c0ca4576f\"},\"breadcrumb\":{\"@id\":\"https:\/\/golangbyexamples.com\/sort-custom-struct-collection-golang\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/golangbyexamples.com\/sort-custom-struct-collection-golang\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/golangbyexamples.com\/sort-custom-struct-collection-golang\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/golangbyexamples.com\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Sort a Custom Struct in Go (Golang)\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/golangbyexamples.com\/#website\",\"url\":\"https:\/\/golangbyexamples.com\/\",\"name\":\"Welcome To Golang By Example\",\"description\":\"\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/golangbyexamples.com\/?s={search_term_string}\"},\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"en-US\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/golangbyexamples.com\/#\/schema\/person\/8833ea7638dafd763cb1db6c0ca4576f\",\"name\":\"admin\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/golangbyexamples.com\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/?s=96&d=mm&r=g\",\"caption\":\"admin\"},\"url\":\"https:\/\/golangbyexamples.com\/author\/admin\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Sort a Custom Struct in Go (Golang) - Welcome To Golang By Example","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:\/\/golangbyexamples.com\/sort-custom-struct-collection-golang\/","og_locale":"en_US","og_type":"article","og_title":"Sort a Custom Struct in Go (Golang) - Welcome To Golang By Example","og_description":"Table of Contents IntroductionFull Working Code: Introduction GO has a sort package that provides utility primitives for the sorting of slices and user-defined types. Any collection can be sorted by the Sort...","og_url":"https:\/\/golangbyexamples.com\/sort-custom-struct-collection-golang\/","og_site_name":"Welcome To Golang By Example","article_published_time":"2019-12-27T16:26:04+00:00","article_modified_time":"2019-12-27T16:28:54+00:00","author":"admin","twitter_card":"summary_large_image","twitter_misc":{"Written by":"admin","Est. reading time":"2 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/golangbyexamples.com\/sort-custom-struct-collection-golang\/","url":"https:\/\/golangbyexamples.com\/sort-custom-struct-collection-golang\/","name":"Sort a Custom Struct in Go (Golang) - Welcome To Golang By Example","isPartOf":{"@id":"https:\/\/golangbyexamples.com\/#website"},"datePublished":"2019-12-27T16:26:04+00:00","dateModified":"2019-12-27T16:28:54+00:00","author":{"@id":"https:\/\/golangbyexamples.com\/#\/schema\/person\/8833ea7638dafd763cb1db6c0ca4576f"},"breadcrumb":{"@id":"https:\/\/golangbyexamples.com\/sort-custom-struct-collection-golang\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/golangbyexamples.com\/sort-custom-struct-collection-golang\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/golangbyexamples.com\/sort-custom-struct-collection-golang\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/golangbyexamples.com\/"},{"@type":"ListItem","position":2,"name":"Sort a Custom Struct in Go (Golang)"}]},{"@type":"WebSite","@id":"https:\/\/golangbyexamples.com\/#website","url":"https:\/\/golangbyexamples.com\/","name":"Welcome To Golang By Example","description":"","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/golangbyexamples.com\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/golangbyexamples.com\/#\/schema\/person\/8833ea7638dafd763cb1db6c0ca4576f","name":"admin","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/golangbyexamples.com\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/?s=96&d=mm&r=g","caption":"admin"},"url":"https:\/\/golangbyexamples.com\/author\/admin\/"}]}},"jetpack_featured_media_url":"","jetpack_publicize_connections":[],"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/paOs1b-gh","amp_validity":null,"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/posts\/1009","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/comments?post=1009"}],"version-history":[{"count":3,"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/posts\/1009\/revisions"}],"predecessor-version":[{"id":1013,"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/posts\/1009\/revisions\/1013"}],"wp:attachment":[{"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/media?parent=1009"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/categories?post=1009"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/tags?post=1009"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}