New Features in C# 2.0—Type-Safe List: How do I do that?

Microsoft .NET Framework, ASP.NET, Visual C# (CSharp, C Sharp, C-Sharp) Developer Training, Visual Studio

How do I do that?

To get a feel for the new generic types in .NET 2.0, let’s use the typesafe List class to create a list of employees. To execute this lab, open Visual Studio 2005, create a new C# Console application, and name it CreateATypeSafeList. Replace the code Visual Studio 2005 creates for you with the code in Example 1-1.

Example 1-1. Creating a type-safe list

using System;
using System.Collections.Generic;
 
namespace CreateATypeSafeList
{
  // a class to store in the List
  public class Employee
  {
    private int empID;
    // constructor
    public Employee(int empID)
    {
      this.empID = empID;
    }
    // override the ToString method to
    // display this employee's id
    public override string ToString( )
    {
      return empID.ToString( );
    }
  } // end class
 
  // Test driver class
  public class Program
  {
    // entry point
    static void Main( )
    {
      // Declare the type safe list (of Employee objects)
      List<Employee> empList = new List<Employee>( );
 
      // Declare a second type safe list (of integers)
      List<int> intList = new List<int>( );
 
      // populate the Lists
      for (int i = 0; i < 5; i++)
      {
        empList.Add(new Employee(i + 100));
        intList.Add(i * 5);
        // empList.Add(i * 5); // see "What About" section below
      }
 
      // print the integer list
      foreach (int i in intList)
      {
        Console.Write("{0} ", i.ToString( ));
      }
      Console.WriteLine("\n");
 
      // print the Employee List
      foreach (Employee employee in empList)
      {
        Console.Write("{0} ", employee.ToString( ));
      }
      Console.WriteLine("\n");
    }
  }
}

Output:

0 5 10 15 20
100 101 102 103 104