title: Usage of Var Pattern in C# 7
body: <p>I've seen this example of var pattern in the new C# 7</p>
  
  <pre><code>if (o is var x) Console.WriteLine($"it's a var pattern with the type {x?.GetType()?.Name}");
  </code></pre>
  
  <p>What is the different of just use:</p>
  
  <pre><code>var x = o;
  Console.WriteLine($"it's a var pattern with the type {x?.GetType()?.Name}");
  </code></pre>
  
  <p>And when this pattern is an useful solution.</p>