Primary

This allows you to use the class declaration to specify the most common constructor

class Person(string name, int age) 
{ 
   private string _name = name; 
   private int _age = age; 
} 

instead of

class Person(string name, int age) 
{ 
   public Person (string name, int age) 
   { 
      _name = name; 
      _age = age; 
   } 
}