Generics in C#

In my last article I focused on issues of typesafety and reusability when using ArrayLists.In this article we shall focus on how these issues of type safety andreusability are very nicely handled by Generics. All with the help ofcode again :

using System;
using System.Collections.Generic;
using System.Text;
 

namespace GenericsSample
{
class Person
{
int _Age;

public int Age
{
get { return _Age; }
set { _Age = value; }
}
String _Name;

public String Name
{
get { return _Name; }
set { _Name = value; }
}
String _Address;

public String Address
{
get { return _Address; }
set { _Address = value; }
}
String _Company;

public String Company
{
get { return _Company; }
set { _Company = value; }
}

public Person() { }
public Person(String Name)
{
this.Name = Name;
this.Age = 0;
this.Address = String.Empty;
this.Company = String.Empty;
}
public Person(String Name, int Age, String Address)
{
this.Name = Name;
this.Age = Age;
this.Address = Address;
}

}

class Program
{
static void Main(string[] args)
{
//Generic List Creation
//List is a Generic Class provided by .Net Framework 2.0
//System.Collections.Generics is the Namespace.

List<person> myPerson = new List<person>();
myPerson.Add(new Person("Saurabh"));
myPerson.Add(new Person("Manu"));
myPerson.Add(new Person("SomeOne", 24, "Gurgaon"));
myPerson.Add(new Person("SomeoneElse", 24, "Gurgaon"));

//myPerson.Add(new Car());// This is A Compile Time Error

foreach (Person p in myPerson)
{
Console.WriteLine(p.Name);
Console.WriteLine(p.Age);
Console.WriteLine(p.Address);
Console.WriteLine(p.Company);
}
Console.ReadLine();
}
}
}

Two classes can be seen in this code. ClassPerson is the class of which we want to create list for, and classProgram is the main class where we actually create the list of personsand operate upon them.

How Generics tackle the issues posed by ArrayLists?

In the above code example Generic List classhas been used to “contain” objects of type Person. At any time we canwe can have the Generic List contain any other type, as below:-