{"id":4145,"date":"2020-09-30T23:01:21","date_gmt":"2020-09-30T17:31:21","guid":{"rendered":"https:\/\/golangbyexamples.com\/?p=4145"},"modified":"2020-09-30T23:02:20","modified_gmt":"2020-09-30T17:32:20","slug":"boolean-constant-go","status":"publish","type":"post","link":"https:\/\/golangbyexamples.com\/boolean-constant-go\/","title":{"rendered":"Boolean constant 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\/boolean-constant-go\/#Overview\" title=\"Overview\">Overview<\/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\/boolean-constant-go\/#Example\" title=\"Example\">Example<\/a><ul class=\"ez-toc-list-level-2\"><li class=\"ez-toc-heading-level-2\"><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/golangbyexamples.com\/boolean-constant-go\/#Typed_boolean_constant\" title=\"Typed boolean constant\">Typed boolean constant<\/a><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-2\"><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/golangbyexamples.com\/boolean-constant-go\/#Untyped_named_boolean_constant\" title=\"Untyped named boolean constant\">Untyped named boolean constant<\/a><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-2\"><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/golangbyexamples.com\/boolean-constant-go\/#Untyped_unnamed_boolean_constant\" title=\"Untyped unnamed boolean constant\">Untyped unnamed boolean constant<\/a><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Overview\"><\/span><strong>Overview<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<p class=\"has-medium-font-size\">There are two untyped boolean constant <strong>true<\/strong> and <strong>false<\/strong>.\u00a0 Below is the program illustrating a boolean constant.\u00a0<\/p>\n\n\n\n<p class=\"has-medium-font-size\"> To better understand boolean constant in golang it is important to understand typed and untyped constant in go. Please refer to this article for that &#8211; <a href=\"https:\/\/golangbyexamples.com\/typed-untyped-constant-golang\">https:\/\/golangbyexamples.com\/typed-untyped-constant-golang<\/a>\/<\/p>\n\n\n\n<p class=\"has-medium-font-size\"><br>Once you have gone through the article you would have understood that constant can be declared in three ways<\/p>\n\n\n\n<ul class=\"has-medium-font-size wp-block-list\"><li>Typed&nbsp; constant<\/li><li>Untyped unnamed&nbsp; constant<\/li><li>Untyped named constant<\/li><\/ul>\n\n\n\n<p class=\"has-medium-font-size\">It is the same case with boolean as well. Let&#8217;s see a program to understand it<\/p>\n\n\n\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Example\"><\/span><strong>Example<\/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 \"fmt\"\n\nfunc main() {\n\ttype myBool bool\n\n\t\/\/Typed Boolean constant\n\tconst aa bool = true\n\tvar uu = aa\n\tfmt.Println(\"Typed named boolean constant\")\n\tfmt.Printf(\"uu: Type: %T Value: %v\\n\\n\", uu, uu)\n\n\t\/\/Below line will raise a compilation error\n\t\/\/var vv myBool = aa\n\n\t\/\/Untyped named boolean constant\n\tconst bb = true\n\n\tvar ww myBool = bb\n\tvar xx = bb\n\tfmt.Println(\"Untyped named boolean constant\")\n\tfmt.Printf(\"ww: Type: %T Value: %v\\n\", ww, ww)\n\tfmt.Printf(\"xx: Type: %T Value: %v\\n\\n\", xx, xx)\n\n\t\/\/Untyped unnamed boolean constant\n\tvar yy myBool = true\n\tvar zz = true\n\tfmt.Println(\"Untyped unnamed boolean constant\")\n\tfmt.Printf(\"yy: Type: %T Value: %v\\n\", yy, yy)\n\tfmt.Printf(\"zz: Type: %T Value: %v\\n\", zz, zz)\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\">Typed named boolean constant\nuu: Type: bool Value: true\n\nUntyped named boolean constant\nww: Type: main.myBool Value: true\nxx: Type: bool Value: true\n\nUntyped unnamed boolean constant\nyy: Type: main.myBool Value: true\nzz: Type: bool Value: true<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">In the above program, we created a new type <strong>myBool<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">type myBool bool<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">Also above program shows the example of<\/p>\n\n\n\n<ul class=\"has-medium-font-size wp-block-list\"><li>Typed boolean constant<\/li><li>Untyped unnamed boolean constant<\/li><li>Untyped named boolean constant<\/li><\/ul>\n\n\n\n<p class=\"has-medium-font-size\">Let&#8217;s understand each of them and their behaviour<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Typed_boolean_constant\"><\/span><strong>Typed boolean constant<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"has-medium-font-size\">It is defined as below<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">const aa bool = true<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">Notice in above that below line will cause a compilation error. This is because variable <strong>aa<\/strong> is of typed <strong>boolean<\/strong> constant . So below line will cause compilation error as it cannot be assigned to variable of type <strong>myBool<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">var v mybool = aa<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">But typed string constant can be assigned to a variable created with <strong>var<\/strong> keyword like below<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">var uu = aa<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Untyped_named_boolean_constant\"><\/span><strong>Untyped named boolean constant<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"has-medium-font-size\">It is defined as below<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">const bb = true<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">Untyped named string constant can be assigned to variable of type <strong>myBool<\/strong> as well variable created with <strong>var<\/strong> keyword because it is untyped so type of the constant will be decided depending upon the type of variable they are being assigned to.<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">var ww mybool = bb\nvar xx = bb<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Untyped_unnamed_boolean_constant\"><\/span><strong>Untyped unnamed boolean constant<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"has-medium-font-size\">It is like below<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">true<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">Untyped unnamed string constant can be assigned to variable of type <strong>myBool<\/strong> as well variable created with <strong>var<\/strong> keyword because it is untyped so type of the constant will be decided depending upon the type of variable they are being assigned to.<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">var yy mybool = true\nvar zz = true<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Table of Contents OverviewExampleTyped boolean constantUntyped named boolean constantUntyped unnamed boolean constant Overview There are two untyped boolean constant true and false.\u00a0 Below is the program illustrating a boolean constant.\u00a0 To better&#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":[3,4],"class_list":["post-4145","post","type-post","status-publish","format-standard","hentry","category-tech","tag-go","tag-golang"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v22.7 - 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