C# Update a List from Another List

Answer 1

to elaborate aershov's answer:

ListA.Where(d => d.Name == x.Name).First().CopyFrom(x);

then in your Person class:

public class Person
{
   // ... Name, Id, Age properties...

   public void CopyFrom(Person p)
   {
      this.Name = p.Name;
      this.Id = p.Id;
      this.Age = p.Age;
   }
}

of course check nulls and everything.