C# Linq intersect/except with one part of object

Question

I\'ve got a class:

class ThisClass
{
  private string a {get; set;}
  private string b {get; set;}
}

I would like to use the Intersect and

Answer 1

I know this is old but couldn't you also just override the Equals & GetHashCode on the class itself?

class ThisClass
{
  public string a {get; set;}
  private string b {get; set;}

  public override bool Equals(object obj)
  {
    // If you only want to compare on a
    ThisClass that = (ThisClass)obj;
    return string.Equals(a, that.a/* optional: not case sensitive? */);
  }

  public override int GetHashCode()
  {
    return a.GetHashCode();
  }
}