{"id":162,"date":"2020-09-03T16:11:48","date_gmt":"2020-09-03T16:11:48","guid":{"rendered":"https:\/\/www.guyhowto.com\/?p=162"},"modified":"2023-12-20T18:42:12","modified_gmt":"2023-12-20T18:42:12","slug":"go-pointers","status":"publish","type":"post","link":"https:\/\/www.guyhowto.com\/go-pointers\/","title":{"rendered":"What is a pointer in Go Language?"},"content":{"rendered":"<ul>\n<li>Pointers in Go programming language is a variable which is used to keep the memory address of another variable.<\/li>\n<li>Pointers in Golang can be termed as the special variable. The variables are utilized to save some data at a specific memory address in the system.<\/li>\n<li>Like any constant or variable, you have to declare a pointer before you can use it to store any variable speech.<\/li>\n<\/ul>\n<p><strong>Declaring a pointer<\/strong><\/p>\n<blockquote><p>var var_name *var-type<\/p><\/blockquote>\n<p><strong>for example:<\/strong><\/p>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"golang\">var intp *int\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\r\n\r\nvar fltp *float32<\/pre>\n<p><strong>Note: <\/strong>A newly declared pointer variable that has not yet been assigned to a variable has the <strong>nil<\/strong> value.<\/p>\n<h5><strong>An example of a pointer<\/strong><\/h5>\n<p>In this example, we simply get the address of a variable by using \u2018&amp;\u2019:<\/p>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"golang\">package main\r\n\r\n\r\n\r\n\r\nimport \"fmt\"\r\n\r\n\r\n\r\n\r\nfunc main() {\r\n\r\n\u00a0\u00a0\u00a0 x := 10\r\n\r\n\u00a0\u00a0\u00a0 fmt.Println(\"pointer address:\", &amp;x)\r\n\r\n}<\/pre>\n<p><strong>Output:<\/strong><\/p>\n<blockquote><p>pointer address: 0xc42000e1f8<\/p><\/blockquote>\n<h5><strong>Assigning and displaying value of pointer example<\/strong><\/h5>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"golang\">package main\r\n\r\n\r\n\r\n\r\nimport \"fmt\"\r\n\r\n\r\n\r\n\r\nfunc main() {\r\n\r\n\r\n\r\n\r\n\u00a0\u00a0\u00a0 var intX int = 35\r\n\r\n\u00a0\u00a0\u00a0\r\n\r\n\u00a0\u00a0\u00a0 \/\/Declaring a pointer variable\u00a0\r\n\r\n\u00a0\u00a0\u00a0 var ptrX *int\r\n\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\r\n\r\n\u00a0\u00a0\u00a0 ptrX = &amp;intX\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\u00a0\u00a0\u00a0 fmt.Println(\"intX variable address = \", &amp;intX)\r\n\r\n\u00a0\u00a0\u00a0 fmt.Println(\"Pointer variable ptrX value= \", ptrX)\r\n\r\n\u00a0\u00a0\u00a0 fmt.Println(\"Value of intX = \", intX)\u00a0\u00a0\u00a0\u00a0\r\n\r\n}<\/pre>\n<p><strong>Output:<\/strong><\/p>\n<blockquote><p>intX variable address =\u00a0 0xc42000e1f8<\/p>\n<p>Pointer variable ptrX value=\u00a0 0xc42000e1f8<\/p>\n<p>Value of intX =\u00a0 35<\/p><\/blockquote>\n<h5><strong>Changing the value of pointer example<\/strong><\/h5>\n<p>We will change the value of the pointer and display it:<\/p>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"golang\">package main\u00a0\r\n\r\nimport (\"fmt\")\u00a0\r\n\r\nfunc main() {\u00a0\r\n\r\n\u00a0\u00a0 ptrX := new(int)\u00a0\r\n\r\n\u00a0\u00a0 fmt.Println(\"Before: \",*ptrX)\u00a0\r\n\r\n\u00a0\u00a0 *ptrX = 35\r\n\r\n\u00a0\u00a0 fmt.Println(\"Value of pointer after change: \",*ptrX)\u00a0\r\n\r\n}<\/pre>\n<p><strong>Output:<\/strong><\/p>\n<blockquote><p>Before:\u00a0 0<\/p>\n<p>Value of pointer after change:\u00a0 35<\/p><\/blockquote>\n<h5><strong>An example of an array with pointer<\/strong><\/h5>\n<p><strong>This example shows using array with pointer:<\/strong><\/p>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"golang\">package main\r\n\r\n\r\n\r\n\r\nimport \"fmt\"\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\nfunc main() {\r\n\r\nconst lim int = 3\r\n\r\n\u00a0\u00a0 arr:= [3]int{10,20,30}\r\n\r\n\u00a0\u00a0 var i int\r\n\r\n\u00a0\u00a0 var ptr [lim]*int;\r\n\r\n\r\n\r\n\r\n\u00a0\u00a0 for\u00a0 i = 0; i &lt; lim; i++ {\r\n\r\n\u00a0\u00a0\u00a0\u00a0\u00a0 ptr[i] = &amp;arr[i]\r\n\r\n\u00a0\u00a0 }\r\n\r\n\u00a0\u00a0 for\u00a0 i = 0; i &lt; lim; i++ {\r\n\r\n\u00a0\u00a0\u00a0\u00a0\u00a0 fmt.Printf(\"Value of arr[%d] = %d\\n\", i,*ptr[i] )\r\n\r\n\u00a0\u00a0 }\r\n\r\n}<\/pre>\n<p><strong>Output:<\/strong><\/p>\n<blockquote><p>Value of arr[0] = 10<\/p>\n<p>Value of arr[1] = 20<\/p>\n<p>Value of arr[2] = 30<\/p><\/blockquote>\n<h5><strong>An example of passing pointers to function<\/strong><\/h5>\n<p>In this example, we have declared two variables and assigned them values. Then we passed those to a function and swap the numbers using pointers:<\/p>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"golang\">package main\r\n\r\n\r\n\r\n\r\nimport (\"fmt\")\r\n\r\n\r\n\r\n\r\nfunc main() {\r\n\r\n\r\n\r\n\r\n\u00a0\u00a0 var numa int = 100\r\n\r\n\u00a0\u00a0 var numb int= 200\r\n\r\n\r\n\r\n\r\n\u00a0\u00a0 fmt.Printf(\"Value of numa before swap : %d\\n\", numa )\r\n\r\n\u00a0\u00a0 fmt.Printf(\"Value of numb before swap : %d\\n\", numb )\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\u00a0\u00a0 swapByPointer(&amp;numa, &amp;numb);\r\n\r\n\u00a0\u00a0 fmt.Printf(\"\\n\\n\" )\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\r\n\r\n\u00a0\u00a0 fmt.Printf(\"Value of numa after swap : %d\\n\", numa )\r\n\r\n\u00a0\u00a0 fmt.Printf(\"Value of numb aftere swap : %d\\n\", numb )\r\n\r\n}\r\n\r\nfunc swapByPointer(numx *int, numy *int) {\r\n\r\n\u00a0\u00a0 var temp int\r\n\r\n\u00a0\u00a0 temp = *numx\u00a0\u00a0\u00a0\r\n\r\n\u00a0\u00a0 *numx = *numy\u00a0\u00a0\r\n\r\n\u00a0\u00a0 *numy = temp\u00a0\u00a0\u00a0\r\n\r\n}<\/pre>\n<p>&nbsp;<\/p>\n<p><strong>Output:<\/strong><\/p>\n<blockquote><p>Value of numa before swap : 100<\/p>\n<p>Value of numb before swap : 200<\/p>\n<p>&nbsp;<\/p>\n<p>Value of numa after swap : 200<\/p>\n<p>Value of numb after swap : 100<\/p><\/blockquote>\n<h5><strong>Why we need pointers in Go?<\/strong><\/h5>\n<p>To comprehend this need, first, we must understand the idea of variables. Variable are the names given to some memory location where the actual data is saved.<\/p>\n<p>To access the saved data we want the address of that particular memory location. To remember all of the memory addresses (Hexadecimal Format) manually is an overhead that is why we use variables to store variables and data can be retrieved by simply using their name.<\/p>\n<p>The Go also allows saving a hexadecimal number to a variable using the literal expression i.e. number beginning from 0x is a hexadecimal number.<\/p>\n<p>With pointers, we could pass a reference to a variable (as an instance, as a parameter to a function), rather than passing a copy of the factor which may decrease memory usage and improve efficiency.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Pointers in Golang can be termed as the special variable. The variables are utilized to save some data at a specific memory address in the system. <\/p>\n","protected":false},"author":3,"featured_media":92,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9],"tags":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v21.7 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>5 Examples to Learn Go Pointers<\/title>\n<meta name=\"description\" content=\"Pointers in Golang can be termed as the special variable. The variables are utilized to save some data at a specific memory address in the system.\" \/>\n<meta name=\"robots\" content=\"noindex, follow\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"5 Examples to Learn Go Pointers\" \/>\n<meta property=\"og:description\" content=\"Pointers in Golang can be termed as the special variable. The variables are utilized to save some data at a specific memory address in the system.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.guyhowto.com\/go-pointers\/\" \/>\n<meta property=\"article:published_time\" content=\"2020-09-03T16:11:48+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2023-12-20T18:42:12+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.guyhowto.com\/wp-content\/uploads\/2020\/08\/2_1_Go-logo.png\" \/>\n\t<meta property=\"og:image:width\" content=\"393\" \/>\n\t<meta property=\"og:image:height\" content=\"163\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"author\" content=\"Nimar_geek\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Nimar_geek\" \/>\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:\/\/www.guyhowto.com\/go-pointers\/\",\"url\":\"https:\/\/www.guyhowto.com\/go-pointers\/\",\"name\":\"5 Examples to Learn Go Pointers\",\"isPartOf\":{\"@id\":\"https:\/\/www.guyhowto.com\/#website\"},\"datePublished\":\"2020-09-03T16:11:48+00:00\",\"dateModified\":\"2023-12-20T18:42:12+00:00\",\"author\":{\"@id\":\"https:\/\/www.guyhowto.com\/#\/schema\/person\/d00f8de6aca9142594eaf8075922f9fc\"},\"description\":\"Pointers in Golang can be termed as the special variable. The variables are utilized to save some data at a specific memory address in the system.\",\"breadcrumb\":{\"@id\":\"https:\/\/www.guyhowto.com\/go-pointers\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.guyhowto.com\/go-pointers\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.guyhowto.com\/go-pointers\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.guyhowto.com\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Go\",\"item\":\"https:\/\/www.guyhowto.com\/topics\/go\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"What is a pointer in Go Language?\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.guyhowto.com\/#website\",\"url\":\"https:\/\/www.guyhowto.com\/\",\"name\":\"\",\"description\":\"\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.guyhowto.com\/?s={search_term_string}\"},\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"en-US\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.guyhowto.com\/#\/schema\/person\/d00f8de6aca9142594eaf8075922f9fc\",\"name\":\"Nimar_geek\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.guyhowto.com\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/1e9b2e17f20f7f4a7ee6314424920f95?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/1e9b2e17f20f7f4a7ee6314424920f95?s=96&d=mm&r=g\",\"caption\":\"Nimar_geek\"}}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"5 Examples to Learn Go Pointers","description":"Pointers in Golang can be termed as the special variable. The variables are utilized to save some data at a specific memory address in the system.","robots":{"index":"noindex","follow":"follow"},"og_locale":"en_US","og_type":"article","og_title":"5 Examples to Learn Go Pointers","og_description":"Pointers in Golang can be termed as the special variable. The variables are utilized to save some data at a specific memory address in the system.","og_url":"https:\/\/www.guyhowto.com\/go-pointers\/","article_published_time":"2020-09-03T16:11:48+00:00","article_modified_time":"2023-12-20T18:42:12+00:00","og_image":[{"width":393,"height":163,"url":"https:\/\/www.guyhowto.com\/wp-content\/uploads\/2020\/08\/2_1_Go-logo.png","type":"image\/png"}],"author":"Nimar_geek","twitter_card":"summary_large_image","twitter_misc":{"Written by":"Nimar_geek","Est. reading time":"2 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/www.guyhowto.com\/go-pointers\/","url":"https:\/\/www.guyhowto.com\/go-pointers\/","name":"5 Examples to Learn Go Pointers","isPartOf":{"@id":"https:\/\/www.guyhowto.com\/#website"},"datePublished":"2020-09-03T16:11:48+00:00","dateModified":"2023-12-20T18:42:12+00:00","author":{"@id":"https:\/\/www.guyhowto.com\/#\/schema\/person\/d00f8de6aca9142594eaf8075922f9fc"},"description":"Pointers in Golang can be termed as the special variable. The variables are utilized to save some data at a specific memory address in the system.","breadcrumb":{"@id":"https:\/\/www.guyhowto.com\/go-pointers\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.guyhowto.com\/go-pointers\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/www.guyhowto.com\/go-pointers\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.guyhowto.com\/"},{"@type":"ListItem","position":2,"name":"Go","item":"https:\/\/www.guyhowto.com\/topics\/go\/"},{"@type":"ListItem","position":3,"name":"What is a pointer in Go Language?"}]},{"@type":"WebSite","@id":"https:\/\/www.guyhowto.com\/#website","url":"https:\/\/www.guyhowto.com\/","name":"","description":"","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.guyhowto.com\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/www.guyhowto.com\/#\/schema\/person\/d00f8de6aca9142594eaf8075922f9fc","name":"Nimar_geek","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.guyhowto.com\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/1e9b2e17f20f7f4a7ee6314424920f95?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/1e9b2e17f20f7f4a7ee6314424920f95?s=96&d=mm&r=g","caption":"Nimar_geek"}}]}},"_links":{"self":[{"href":"https:\/\/www.guyhowto.com\/wp-json\/wp\/v2\/posts\/162"}],"collection":[{"href":"https:\/\/www.guyhowto.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.guyhowto.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.guyhowto.com\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.guyhowto.com\/wp-json\/wp\/v2\/comments?post=162"}],"version-history":[{"count":1,"href":"https:\/\/www.guyhowto.com\/wp-json\/wp\/v2\/posts\/162\/revisions"}],"predecessor-version":[{"id":5577,"href":"https:\/\/www.guyhowto.com\/wp-json\/wp\/v2\/posts\/162\/revisions\/5577"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.guyhowto.com\/wp-json\/wp\/v2\/media\/92"}],"wp:attachment":[{"href":"https:\/\/www.guyhowto.com\/wp-json\/wp\/v2\/media?parent=162"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.guyhowto.com\/wp-json\/wp\/v2\/categories?post=162"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.guyhowto.com\/wp-json\/wp\/v2\/tags?post=162"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}