{"componentChunkName":"component---src-templates-post-template-js","path":"/posts/en/2016-06-30-static-properties-class-syntax/","webpackCompilationHash":"a3ac22c47fe06e2afd02","result":{"data":{"markdownRemark":{"id":"2de91866-c380-5828-a408-f92c1cbf981b","html":"<h3 id=\"problem\"><a href=\"#problem\" aria-label=\"problem permalink\" class=\"anchor\"><svg aria-hidden=\"true\" focusable=\"false\" height=\"16\" version=\"1.1\" viewBox=\"0 0 16 16\" width=\"16\"><path fill-rule=\"evenodd\" d=\"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"></path></svg></a>Problem</h3>\n<p>You want to define a static property inside a “class”.</p>\n<h3 id=\"ingredients\"><a href=\"#ingredients\" aria-label=\"ingredients permalink\" class=\"anchor\"><svg aria-hidden=\"true\" focusable=\"false\" height=\"16\" version=\"1.1\" viewBox=\"0 0 16 16\" width=\"16\"><path fill-rule=\"evenodd\" d=\"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"></path></svg></a>Ingredients</h3>\n<ul>\n<li>1 “class”</li>\n<li>1 property</li>\n</ul>\n<h3 id=\"directions\"><a href=\"#directions\" aria-label=\"directions permalink\" class=\"anchor\"><svg aria-hidden=\"true\" focusable=\"false\" height=\"16\" version=\"1.1\" viewBox=\"0 0 16 16\" width=\"16\"><path fill-rule=\"evenodd\" d=\"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"></path></svg></a>Directions</h3>\n<ol>\n<li>\n<p>Create a “class”.</p>\n<div class=\"gatsby-highlight\" data-language=\"javascript\"><pre class=\"language-javascript\"><code class=\"language-javascript\"><span class=\"token keyword\">class</span> <span class=\"token class-name\">SomeClass</span> <span class=\"token punctuation\">{</span>\n  <span class=\"token function\">constructor</span><span class=\"token punctuation\">(</span><span class=\"token parameter\">property</span><span class=\"token punctuation\">)</span> <span class=\"token punctuation\">{</span>\n    <span class=\"token keyword\">this</span><span class=\"token punctuation\">.</span>property <span class=\"token operator\">=</span> property<span class=\"token punctuation\">;</span>\n  <span class=\"token punctuation\">}</span>\n<span class=\"token punctuation\">}</span></code></pre></div>\n</li>\n</ol>\n<!-- more -->\n<ol start=\"2\">\n<li>\n<p>Add the property that should be static directly to the “class”.</p>\n<div class=\"gatsby-highlight\" data-language=\"javascript\"><pre class=\"language-javascript\"><code class=\"language-javascript\"><span class=\"token keyword\">class</span> <span class=\"token class-name\">SomeClass</span> <span class=\"token punctuation\">{</span>\n  <span class=\"token function\">constructor</span><span class=\"token punctuation\">(</span><span class=\"token parameter\">property</span><span class=\"token punctuation\">)</span> <span class=\"token punctuation\">{</span>\n    <span class=\"token keyword\">this</span><span class=\"token punctuation\">.</span>property <span class=\"token operator\">=</span> property<span class=\"token punctuation\">;</span>\n  <span class=\"token punctuation\">}</span>\n<span class=\"token punctuation\">}</span>\nSomeClass<span class=\"token punctuation\">.</span><span class=\"token constant\">STATIC_PROPERTY</span> <span class=\"token operator\">=</span> <span class=\"token string\">'This is a static property.'</span><span class=\"token punctuation\">;</span></code></pre></div>\n</li>\n<li>\n<p>Voilá, there you got your static property.</p>\n<div class=\"gatsby-highlight\" data-language=\"javascript\"><pre class=\"language-javascript\"><code class=\"language-javascript\">console<span class=\"token punctuation\">.</span><span class=\"token function\">log</span><span class=\"token punctuation\">(</span>SomeClass<span class=\"token punctuation\">.</span><span class=\"token constant\">STATIC_PROPERTY</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">;</span>  <span class=\"token comment\">// \"This is a static property.\"</span></code></pre></div>\n</li>\n</ol>\n<h3 id=\"notes\"><a href=\"#notes\" aria-label=\"notes permalink\" class=\"anchor\"><svg aria-hidden=\"true\" focusable=\"false\" height=\"16\" version=\"1.1\" viewBox=\"0 0 16 16\" width=\"16\"><path fill-rule=\"evenodd\" d=\"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"></path></svg></a>Notes</h3>\n<ul>\n<li>\n<p>Static properties cannot be accessed via an instance:</p>\n<div class=\"gatsby-highlight\" data-language=\"javascript\"><pre class=\"language-javascript\"><code class=\"language-javascript\"><span class=\"token keyword\">let</span> instance <span class=\"token operator\">=</span> <span class=\"token keyword\">new</span> <span class=\"token class-name\">SomeClass</span><span class=\"token punctuation\">(</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">;</span>\n<span class=\"token comment\">// console.log(instance.STATIC_PROPERTY);  // won't work</span></code></pre></div>\n</li>\n<li>\n<p>To access a static property based on an instance you need to access it via the <code class=\"language-text\">constructor</code> property:</p>\n<div class=\"gatsby-highlight\" data-language=\"javascript\"><pre class=\"language-javascript\"><code class=\"language-javascript\"><span class=\"token keyword\">let</span> instance <span class=\"token operator\">=</span> <span class=\"token keyword\">new</span> <span class=\"token class-name\">SomeClass</span><span class=\"token punctuation\">(</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">;</span>\nconsole<span class=\"token punctuation\">.</span><span class=\"token function\">log</span><span class=\"token punctuation\">(</span>instance<span class=\"token punctuation\">.</span>constructor<span class=\"token punctuation\">.</span><span class=\"token constant\">STATIC_PROPERTY</span><span class=\"token punctuation\">)</span><span class=\"token punctuation\">;</span></code></pre></div>\n</li>\n</ul>","fields":{"slug":"/posts/en/2016-06-30-static-properties-class-syntax/","tagSlugs":["/tag/java-script/"]},"frontmatter":{"date":"2016-06-30T08:00:00.000Z","description":null,"tags":["JavaScript"],"title":"Define static properties using the class syntax"}}},"pageContext":{"isCreatedByStatefulCreatePages":false,"slug":"/posts/en/2016-06-30-static-properties-class-syntax/"}}}