public static void Main()
foreach(Person p in People)
if(DateTime.TryParse(p.Birthday, out dtBirthday))
Console.WriteLine("{0:D}", dtBirthday);
Console.WriteLine("Invalid Date!");
static Person[] People = new Person[]{
new Person{ FirstName="Andrew", Birthday="5/1/92" },
new Person{ FirstName="Andy", Birthday="11/26/80" },
new Person{ FirstName="Arron", Birthday="08/09/90" },
new Person{ FirstName="David", Birthday="12/29/1989" },
new Person{ FirstName="Stacey", Birthday="11/01/82 12:35:00" },
new Person{ FirstName="Tom", Birthday=null }
public string FirstName{get;set;}
public string Birthday{get;set;}