title: Environment Tag Helper in .NET Core
body: <p>I just create a .net core 2.0 project on my visual studio and found in _Layout.cshtml few new properties like called- "environment". I worked on MVC5 but there was no such properties. What these propertie does? Is it replacement of Rezor Syntax which i used in MVC5 view? Please provide details with doc for use those properties to get started with those. </p>
  
  <p>_Layout.cshtml:</p>
  
  <pre><code> &lt;environment include="Development"&gt;
          &lt;link rel="stylesheet" href="~/lib/bootstrap/dist/css/bootstrap.css" /&gt;
          &lt;link rel="stylesheet" href="~/css/site.css" /&gt;
      &lt;/environment&gt;
      &lt;environment exclude="Development"&gt;
          &lt;link rel="stylesheet" href="https://ajax.aspnetcdn.com/ajax/bootstrap/3.3.7/css/bootstrap.min.css"
                asp-fallback-href="~/lib/bootstrap/dist/css/bootstrap.min.css"
                asp-fallback-test-class="sr-only" asp-fallback-test-property="position" asp-fallback-test-value="absolute" /&gt;
          &lt;link rel="stylesheet" href="~/css/site.min.css" asp-append-version="true" /&gt;
      &lt;/environment&gt;
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/yRTke.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/yRTke.png" alt="pic"></a></p>