using System;
using System.Text;

namespace HelloWorld {
  public class HelloObj {
    private String _name;

    public HelloObj() {
        _name = null;

    }

    public String FirstName {
      get {
        return _name;
      }
      set {
        _name = value;
      }
    }

    public String SayHello() {
      StringBuilder sb = new StringBuilder("Hello ");
      if (_name != null)
         sb.Append(_name);
      else
         sb.Append("World");

      sb.Append("!");
      return sb.ToString();
    }
  }
}

Imports System
Imports System.Text

Namespace HelloWorld
  Public Class HelloObj
    Private _name As String

    Public Sub New
      MyBase.New()
      _name = Nothing
    End Sub

    Public Property FirstName As String
      Get
        Return(_name)
      End get
      Set
        _name = value
       End Set
    End Property

    Public Function SayHello() As String
      Dim sb As New StringBuilder("Hello ")
      If (_name <> Nothing) Then
         sb.Append(_name)
      Else
         sb.Append("World")
      End If
      sb.Append("!")
      Return(sb.ToString())
    End Function
  End Class
End Namespace

import System;
import System.Text;

package HelloWorld {
  public class HelloObj {
    private var _name:String;

    public function HelloObj() {
        _name = null;

    }

    public function get FirstName() : String
    {
        return _name;
    }
    public function set FirstName(value:String) : void
    {
        _name = value;
    }

    public function SayHello() : String {
      sb:StringBuilder = new StringBuilder("Hello ");
      if (_name != null)
         sb.Append(_name);
      else
         sb.Append("World");

      sb.Append("!");
      return sb.ToString();
    }
  }
}