title: What does the ref keyword mean before the return type in C#
body: <p>In the code below, what is the significance of the <code>ref</code> in the <code>GetAge()</code> method signature?    </p>
  
  <pre><code>public class Person
  {
      private int age;
      public ref int GetAge()
      {
          return ref this.age;
      }
  }
  </code></pre>