title: Cannot implicitly convert type 'void' to 'System.Collections.Generic.List<string>'
body: <p>I have the following class to store data.</p>
  
  <pre><code>namespace SumSoftware
  {
      public class Faculty
      {
          public string Name { get; set; }
          public string Dept { get; set; }
          public List&lt;string&gt; subInterest;
  
      }
  }
  </code></pre>
  
  <p>And I am trying to add data from a ListBox and User Input in this fashion.</p>
  
  <pre><code>private void btnTeacherDataAdd_Click(object sender, RoutedEventArgs e)
  {
      List&lt;string&gt; interests = new List&lt;string&gt;();
      if (lstInterest.SelectedItems.Count &gt;= 0)
      {
          foreach (var selectedSubjects in lstInterest.SelectedItems)
          {
                  interests.Add(selectedSubjects.ToString());
          }
      }
  
      SaveDirectory.list_of_faculty.Add(
          new Faculty {
              Name = txtTeacherName.Text, 
              Dept = cmbDepts.Items.CurrentItem.ToString(),
              subInterest = new List&lt;string&gt;().AddRange(interests) //ERROR HERE
          });
  }
  </code></pre>
  
  <p>I am unable to store the contents of the ListBox in my list. How can this be mended?
  Thanks.</p>