{"id":514,"date":"2022-01-10T23:05:40","date_gmt":"2022-01-10T16:05:40","guid":{"rendered":"https:\/\/csharptutorial.net\/?page_id=514"},"modified":"2022-06-03T14:59:12","modified_gmt":"2022-06-03T07:59:12","slug":"csharp-static-classes","status":"publish","type":"page","link":"https:\/\/www.csharptutorial.net\/csharp-tutorial\/csharp-static-classes\/","title":{"rendered":"C# Static Classes"},"content":{"rendered":"\n<p><strong>Summary<\/strong>: in this tutorial, you&#8217;ll learn about the C# static classes and how to use them to define utility classes.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Introduction to C# static classes<\/h2>\n\n\n\n<p>A static class is a <a href=\"https:\/\/csharptutorial.net\/csharp-tutorial\/csharp-class\/\">class<\/a> that cannot be instantiated. Typically, you use a static class to group members that are specific to a class, not an instance of the class.<\/p>\n\n\n\n<p>A common use of a static class is to create a utility class that contains a set of methods and values like the Math library.<\/p>\n\n\n\n<p>A static class has the following characteristics:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>A static class declaration needs to have the <code>static<\/code> keyword.<\/li><li>A static class has only static members including <a href=\"https:\/\/csharptutorial.net\/csharp-tutorial\/csharp-static-field-property\/\">static fields, properties<\/a>, and <a href=\"https:\/\/csharptutorial.net\/csharp-tutorial\/csharp-static-method\/\">methods<\/a>.<\/li><li>A static class cannot have any <a href=\"https:\/\/csharptutorial.net\/csharp-tutorial\/csharp-constructors\/\">instance constructor<\/a> but can have a <a href=\"https:\/\/csharptutorial.net\/csharp-tutorial\/csharp-static-constructor\/\">static constructor<\/a>.<\/li><li>A static class is implicitly <a href=\"https:\/\/csharptutorial.net\/csharp-tutorial\/csharp-sealed\/\">sealed<\/a>. Therefore, you cannot <a href=\"https:\/\/csharptutorial.net\/csharp-tutorial\/csharp-inheritance\/\">subclass<\/a> it.<\/li><\/ul>\n\n\n\n<p>To access members of a static class, you use the class name and the member name.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">C# static class example<\/h2>\n\n\n\n<p>Let&#8217;s see an example of using a static class to define a utility class.<\/p>\n\n\n\n<p>First, define a static class <code>LengthConverter<\/code>:<\/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\">static<\/span> <span class=\"hljs-keyword\">class<\/span> <span class=\"hljs-title\">LengthConverter<\/span>\n{\n    <span class=\"hljs-function\"><span class=\"hljs-keyword\">public<\/span> <span class=\"hljs-keyword\">static<\/span> <span class=\"hljs-keyword\">double<\/span> <span class=\"hljs-title\">FeetToMeters<\/span>(<span class=\"hljs-params\"><span class=\"hljs-keyword\">double<\/span> ft<\/span>)<\/span> =&gt; ft \/ <span class=\"hljs-number\">3.28084<\/span>;\n    <span class=\"hljs-function\"><span class=\"hljs-keyword\">public<\/span> <span class=\"hljs-keyword\">static<\/span> <span class=\"hljs-keyword\">double<\/span> <span class=\"hljs-title\">MetersToFeet<\/span>(<span class=\"hljs-params\"><span class=\"hljs-keyword\">double<\/span> m<\/span>)<\/span> =&gt; m * <span class=\"hljs-number\">3.28084<\/span>;\n\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>The <code>LengthConverter<\/code> static class has two static methods that convert feet to meters and vice versa.<\/p>\n\n\n\n<p>Second, use the <code>LengthConverter<\/code> class:<\/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>\n<span class=\"hljs-keyword\">double<\/span> feet, meters;\n\n<span class=\"hljs-comment\">\/\/ feet to meters<\/span>\nfeet = <span class=\"hljs-number\">100<\/span>;\nmeters = LengthConverter.FeetToMeters(feet);\n\nConsole.WriteLine(<span class=\"hljs-string\">$\"<span class=\"hljs-subst\">{feet}<\/span>ft = <span class=\"hljs-subst\">{meters:<span class=\"hljs-number\">0.<\/span>##}<\/span>m\"<\/span>);\n\n<span class=\"hljs-comment\">\/\/ meters to feet<\/span>\nmeters = <span class=\"hljs-number\">10<\/span>;\nfeet = LengthConverter.MetersToFeet(meters);\n\nConsole.WriteLine(<span class=\"hljs-string\">$\"<span class=\"hljs-subst\">{meters}<\/span>m = <span class=\"hljs-subst\">{feet:<span class=\"hljs-number\">0.<\/span>##}<\/span>ft\"<\/span>);<\/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<p>Output:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-3\" data-shcb-language-name=\"plaintext\" data-shcb-language-slug=\"plaintext\"><span><code class=\"hljs language-plaintext\">100ft = 30.48m\n10m = 32.81ft<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-3\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">plaintext<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">plaintext<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Starting from C# 6, you can access members of a static class without the class if you have a <code>using static<\/code> directive. For example:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-4\" data-shcb-language-name=\"C#\" data-shcb-language-slug=\"cs\"><span><code class=\"hljs language-cs\"><span class=\"hljs-comment\">\/\/ Program.cs<\/span>\n<span class=\"hljs-keyword\">using<\/span> <span class=\"hljs-keyword\">static<\/span> LengthConverter;\n\n<span class=\"hljs-keyword\">double<\/span> feet, meters;\n\n<span class=\"hljs-comment\">\/\/ feet to meters<\/span>\nfeet = <span class=\"hljs-number\">100<\/span>;\nmeters = FeetToMeters(feet);\n\nConsole.WriteLine(<span class=\"hljs-string\">$\"<span class=\"hljs-subst\">{feet}<\/span>ft = <span class=\"hljs-subst\">{meters:<span class=\"hljs-number\">0.<\/span>##}<\/span>m\"<\/span>);\n\n<span class=\"hljs-comment\">\/\/ meters to feet<\/span>\nmeters = <span class=\"hljs-number\">10<\/span>;\nfeet = MetersToFeet(meters);\n\nConsole.WriteLine(<span class=\"hljs-string\">$\"<span class=\"hljs-subst\">{meters}<\/span>m = <span class=\"hljs-subst\">{feet:<span class=\"hljs-number\">0.<\/span>##}<\/span>ft\"<\/span>);<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-4\"><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>A static class cannot be instantiated and subclassed.<\/li><li>A static class only has static members.<\/li><li>Use a static class to define a utility class.<\/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 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