{"id":511,"date":"2022-01-10T17:43:55","date_gmt":"2022-01-10T10:43:55","guid":{"rendered":"https:\/\/csharptutorial.net\/?page_id=511"},"modified":"2022-06-03T15:00:02","modified_gmt":"2022-06-03T08:00:02","slug":"csharp-static-constructor","status":"publish","type":"page","link":"https:\/\/www.csharptutorial.net\/csharp-tutorial\/csharp-static-constructor\/","title":{"rendered":"C# Static Constructors"},"content":{"rendered":"\n<p><strong>Summary<\/strong>: in this tutorial, you&#8217;ll learn about static constructors and how to use them to initialize static members.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Introduction to the C# static constructors<\/h2>\n\n\n\n<p>When creating an instance of a <a href=\"https:\/\/csharptutorial.net\/csharp-tutorial\/csharp-class\/\">class<\/a>, the C# compiler automatically calls the <a href=\"https:\/\/csharptutorial.net\/csharp-tutorial\/csharp-constructors\/\">constructor<\/a>. This constructor is called an instance constructor because it creates a new instance and initializes the instance members.<\/p>\n\n\n\n<p>If you use the <code>static<\/code> keyword to declare a constructor, the constructor becomes a static constructor. Generally, a static constructor initializes <a href=\"https:\/\/csharptutorial.net\/csharp-tutorial\/csharp-static-field-property\/\">static fields and properties<\/a>. <\/p>\n\n\n\n<p>A static constructor is different from an instance constructor in the following ways:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>A static constructor uses the static keyword in the declaration.<\/li><li>A class can have only one static constructor. And the static constructor cannot have any parameters.<\/li><li>A static constructor cannot have an access modifier like <a href=\"https:\/\/csharptutorial.net\/csharp-tutorial\/csharp-public-private\/\">public or private<\/a>.<\/li><\/ul>\n\n\n\n<p>Like a static method, a static constructor cannot access instance members of a class. Therefore, you cannot use the <code>this<\/code> keyword inside the static constructor. However, the static constructor can access instance fields and properties.<\/p>\n\n\n\n<p>Note that a class may have both instance and static constructors.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">C# static constructor example<\/h2>\n\n\n\n<p>The following example defines a class that contains a static constructor:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-1\" data-shcb-language-name=\"C#\" data-shcb-language-slug=\"cs\"><span><code class=\"hljs language-cs\"><span class=\"hljs-keyword\">class<\/span> <span class=\"hljs-title\">RandomNumber<\/span>\n{\n    <span class=\"hljs-keyword\">private<\/span> <span class=\"hljs-keyword\">static<\/span> Random random;\n\n    <span class=\"hljs-function\"><span class=\"hljs-keyword\">static<\/span> <span class=\"hljs-title\">RandomNumber<\/span>(<span class=\"hljs-params\"><\/span>)<\/span>\n    {\n        random = <span class=\"hljs-keyword\">new<\/span> Random();\n    }\n    <span class=\"hljs-function\"><span class=\"hljs-keyword\">public<\/span> <span class=\"hljs-keyword\">int<\/span> <span class=\"hljs-title\">Get<\/span>(<span class=\"hljs-params\"><\/span>)<\/span> =&gt; random.Next();\n}<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-1\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">C#<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">cs<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>How it works.<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>The <code>RandomNumber<\/code> class contains a static field which is an instance of the <code>Random<\/code> class.<\/li><li>The static constructor creates a new instance of the <code>Random<\/code> class and assigns it to the <code>random<\/code> static field. <\/li><li>The <code>Get()<\/code> instance method returns a random integer by calling the <code>Next()<\/code> method of the <code>random<\/code> object.<\/li><\/ul>\n\n\n\n<p>The following program uses the <code>RandomNumber<\/code> class to generate five random integers:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-2\" data-shcb-language-name=\"C#\" data-shcb-language-slug=\"cs\"><span><code class=\"hljs language-cs\"><span class=\"hljs-comment\">\/\/ Program.cs<\/span>\nRandomNumber random = <span class=\"hljs-keyword\">new<\/span>();\n<span class=\"hljs-keyword\">for<\/span> (<span class=\"hljs-keyword\">int<\/span> i = <span class=\"hljs-number\">0<\/span>; i &lt; <span class=\"hljs-number\">5<\/span>; i++)\n{\n    Console.WriteLine(random.Get());\n}<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-2\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">C#<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">cs<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<h2 class=\"wp-block-heading\">Summary<\/h2>\n\n\n\n<ul class=\"wp-block-list\"><li>Use C# static constructors to initialize static members.<\/li><\/ul>\n<div class=\"helpful-block-content\" data-title=\"\">\n\t<header>\n\t\t<div class=\"wth-question\">Was this tutorial helpful ?<\/div>\n\t\t<div class=\"wth-thumbs\">\n\t\t\t<button\n\t\t\t\tdata-post=\"511\"\n\t\t\t\tdata-post-url=\"https:\/\/www.csharptutorial.net\/csharp-tutorial\/csharp-static-constructor\/\"\n\t\t\t\tdata-post-title=\"C# Static Constructors\"\n\t\t\t\tdata-response=\"1\"\n\t\t\t\tclass=\"wth-btn-rounded wth-yes-btn\"\n\t\t\t>\n\t\t\t\t<svg\n\t\t\t\t\txmlns=\"http:\/\/www.w3.org\/2000\/svg\"\n\t\t\t\t\tviewBox=\"0 0 24 24\"\n\t\t\t\t\tfill=\"none\"\n\t\t\t\t\tstroke=\"currentColor\"\n\t\t\t\t\tstroke-width=\"2\"\n\t\t\t\t\tstroke-linecap=\"round\"\n\t\t\t\t\tstroke-linejoin=\"round\"\n\t\t\t\t\tclass=\"feather feather-thumbs-up block w-full h-full\"\n\t\t\t\t>\n\t\t\t\t\t<path\n\t\t\t\t\t\td=\"M14 9V5a3 3 0 0 0-3-3l-4 9v11h11.28a2 2 0 0 0 2-1.7l1.38-9a2 2 0 0 0-2-2.3zM7 22H4a2 2 0 0 1-2-2v-7a2 2 0 0 1 2-2h3\"\n\t\t\t\t\t><\/path>\n\t\t\t\t<\/svg>\n\t\t\t\t<span class=\"sr-only\"> Yes <\/span>\n\t\t\t<\/button>\n\n\t\t\t<button\n\t\t\t\tdata-response=\"0\"\n\t\t\t\tdata-post=\"511\"\n\t\t\t\tdata-post-url=\"https:\/\/www.csharptutorial.net\/csharp-tutorial\/csharp-static-constructor\/\"\n\t\t\t\tdata-post-title=\"C# Static Constructors\"\n\t\t\t\tclass=\"wth-btn-rounded wth-no-btn\"\n\t\t\t>\n\t\t\t\t<svg\n\t\t\t\t\txmlns=\"http:\/\/www.w3.org\/2000\/svg\"\n\t\t\t\t\tviewBox=\"0 0 24 24\"\n\t\t\t\t\tfill=\"none\"\n\t\t\t\t\tstroke=\"currentColor\"\n\t\t\t\t\tstroke-width=\"2\"\n\t\t\t\t\tstroke-linecap=\"round\"\n\t\t\t\t\tstroke-linejoin=\"round\"\n\t\t\t\t>\n\t\t\t\t\t<path\n\t\t\t\t\t\td=\"M10 15v4a3 3 0 0 0 3 3l4-9V2H5.72a2 2 0 0 0-2 1.7l-1.38 9a2 2 0 0 0 2 2.3zm7-13h2.67A2.31 2.31 0 0 1 22 4v7a2.31 2.31 0 0 1-2.33 2H17\"\n\t\t\t\t\t><\/path>\n\t\t\t\t<\/svg>\n\t\t\t\t<span class=\"sr-only\"> No <\/span>\n\t\t\t<\/button>\n\t\t<\/div>\n\t<\/header>\n\n\t<div class=\"wth-form hidden\">\n\t\t<div class=\"wth-form-wrapper\">\n\t\t\t<div class=\"wth-title\"><\/div>\n\t\t\t\n\t\t\t<textarea class=\"wth-message\"><\/textarea>\n\n\t\t\t<button class=\"btn btn-primary wth-btn-submit\">Send<\/button>\n\t\t\t<button class=\"btn wth-btn-cancel\">Cancel<\/button>\n\t\t\n\t\t<\/div>\n\t<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>In this tutorial, you&#8217;ll learn about static constructors and how to use them to initialize static members.<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":7,"menu_order":40,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-511","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.csharptutorial.net\/wp-json\/wp\/v2\/pages\/511","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.csharptutorial.net\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.csharptutorial.net\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.csharptutorial.net\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.csharptutorial.net\/wp-json\/wp\/v2\/comments?post=511"}],"version-history":[{"count":2,"href":"https:\/\/www.csharptutorial.net\/wp-json\/wp\/v2\/pages\/511\/revisions"}],"predecessor-version":[{"id":719,"href":"https:\/\/www.csharptutorial.net\/wp-json\/wp\/v2\/pages\/511\/revisions\/719"}],"up":[{"embeddable":true,"href":"https:\/\/www.csharptutorial.net\/wp-json\/wp\/v2\/pages\/7"}],"wp:attachment":[{"href":"https:\/\/www.csharptutorial.net\/wp-json\/wp\/v2\/media?parent=511"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}