int x;
String s;
String s1, s2;
Object o;
Object obj = new Object();
public String name;

Dim x As Integer
Dim s As String
Dim s1, s2 As String
Dim o 'Implicitly Object
Dim obj As New Object()
Public name As String

var x : int;
var s : String;
var s1 : String, s2 : String;
var o;
var obj : Object = new Object();
var name : String;

Response.Write("foo");

Response.Write("foo")

Response.Write("foo");

// This is a comment

/*
This
is
a
multiline
comment
*/

' This is a comment

' This
' is
' a
' multiline
' comment

// This is a comment

/*
This
is
a
multiline
comment
*/

String s = Request.QueryString["Name"];
String value = Request.Cookies["key"];

Dim s, value As String
s = Request.QueryString("Name")
value = Request.Cookies("Key").Value

'Note that default non-indexed properties
'must be explicitly named in VB

var s : String = Request.QueryString("Name");
var value : String = Request.Cookies("key");

// Default Indexed Property
public String this[String name] {
    get {
        return (String) lookuptable[name];
    }
}

' Default Indexed Property
Public Default ReadOnly Property DefaultProperty(Name As String) As String
    Get
        Return CStr(lookuptable(name))
    End Get
End Property

JScript does not support the creation of indexed or default indexed properties.

To emulate these properties in JScript, use function
declarations instead.  Even though you cannot access the functions using indexed property syntax in C#, it will provide the illusion for VB.

public function Item(name:String) : String {
    return String(lookuptable(name));
}

public String name {

  get {
    ...
    return ...;
  }

  set {
    ... = value;
  }

}

Public Property Name As String

  Get
    ...
    Return ...
  End Get

  Set
    ... = Value
  End Set

End Property

function get name() : String {
    ...
    return ...;
}

function set name(value : String) {
    ... = value;
}

// Declare the Enumeration
public enum MessageSize {

    Small = 0,
    Medium = 1,
    Large = 2
}

// Create a Field or Property
public MessageSize msgsize;

// Assign to the property using the Enumeration values
msgsize = Small;

' Declare the Enumeration
Public Enum MessageSize

    Small = 0
    Medium = 1
    Large = 2
End Enum

' Create a Field or Property
Public MsgSize As MessageSize

' Assign to the property using the Enumeration values
MsgSize = small

// Declare the Enumeration
public enum MessageSize {

    Small = 0,
    Medium = 1,
    Large = 2
}

// Create a Field or Property
public var msgsize:MessageSize;

// Assign to the property using the Enumeration values
msgsize = Small;

foreach ( String s in coll ) {
 ...
}

Dim S As String
For Each S In Coll
 ...
Next

var s:String;
for ( s in coll ) {
 ...
}

// Declare a void return function
void voidfunction() {
 ...
}

// Declare a function that returns a value
String stringfunction() {
 ...
    return (String) val;
}

// Declare a function that takes and returns values
String parmfunction(String a, String b) {
 ...
    return (String) (a + b);
}

// Use the Functions
voidfunction();
String s1 = stringfunction();
String s2 = parmfunction("Hello", "World!");

' Declare a void return function
Sub VoidFunction()
 ...
End Sub

' Declare a function that returns a value
Function StringFunction() As String
 ...
    Return CStr(val)
End Function

' Declare a function that takes and returns values
Function ParmFunction(a As String, b As String) As String
 ...
    Return CStr(A & B)
End Function

' Use the Functions
VoidFunction()
Dim s1 As String = StringFunction()
Dim s2 As String = ParmFunction("Hello", "World!")

// Declare a void return function
function voidfunction() : void {
 ...
}

// Declare a function that returns a value
function stringfunction() : String {
 ...
    return String(val);
}

// Declare a function that takes and returns values
function parmfunction(a:String, b:String) : String {
 ...
    return String(a + b);
}

// Use the Functions
voidfunction();
var s1:String = stringfunction();
var s2:String = parmfunction("Hello", "World!");

// Stand-alone attribute
[STAThread]

// Attribute with parameters
[DllImport("ADVAPI32.DLL")]

// Attribute with named parameters
[DllImport("KERNEL32.DLL", CharSet=CharSet.Auto)]

' Stand-alone attribute


' Attribute with parameters


' Attribute with named parameters

// Stand-alone attribute
STAThreadAttribute

// Attribute with parameters
DllImportAttribute("ADVAPI32.DLL")

// Attribute with named parameters
DllImportAttribute("KERNEL32.DLL", CharSet=CharSet.Auto)

    String[] a = new String[3];
    a[0] = "1";
    a[1] = "2";
    a[2] = "3";

    String[][] a = new String[3][3];
    a[0][0] = "1";
    a[1][0] = "2";
    a[2][0] = "3";

    Dim a(2) As String
    a(0) = "1"
    a(1) = "2"
    a(2) = "3"

    Dim a(2,2) As String
    a(0,0) = "1"
    a(1,0) = "2"
    a(2,0) = "3"

    var a : String[] = new String[3];
    a[0] = "1";
    a[1] = "2";
    a[2] = "3";

    var a : String[][] = new String[3][3];
    a[0][0] = "1";
    a[1][0] = "2";
    a[2][0] = "3";

String s = "Hello World";
int i = 1;
double[] a =  { 3.00, 4.00, 5.00 };

Dim s As String = "Hello World"
Dim i As Integer = 1
Dim a() As Double = { 3.00, 4.00, 5.00 }

var s : String = "Hello World";
var i : int = 1;
var a : double[] = [ 3.00, 4.00, 5.00 ];

if (Request.QueryString != null) {
  ...
}

If Not (Request.QueryString = Nothing)
  ...
End If

if (Request.QueryString != null) {
  ...
}

switch (FirstName) {
  case "John" :
    ...
    break;
  case "Paul" :
    ...
    break;
  case "Ringo" :
    ...
    break;
  default:
    ...
    break;
}

Select Case FirstName
  Case "John"
    ...
  Case "Paul"
    ...
  Case "Ringo"
    ...
  Case Else
    ...
End Select

switch (FirstName) {
  case "John" :
    ...
    break;
  case "Paul" :
    ...
    break;
  case "Ringo" :
    ...
    break;
  default:
    ...
    break;
}

for (int i=0; i<3; i++)
  a(i) = "test";

  Dim I As Integer
  For I = 0 To 2
    a(I) = "test"
  Next

for (var i : int = 0; i < 3; i++)
  a[i] = "test";

int i = 0;
while (i<3) {
  Console.WriteLine(i.ToString());
  i += 1;
}

Dim I As Integer
I = 0
Do While I < 3
  Console.WriteLine(I.ToString())
  I += 1
Loop

var i : int = 0;
while (i < 3) {
  Console.WriteLine(i);
  i += 1;
}

try {
    // Code that throws exceptions
} catch(OverflowException e) {
    // Catch a specific exception
} catch(Exception e) {
    // Catch the generic exceptions
} finally {
    // Execute some cleanup code
}

Try
    ' Code that throws exceptions
Catch E As OverflowException
    ' Catch a specific exception
Catch E As Exception
    ' Catch the generic exceptions
Finally
    ' Execute some cleanup code
End Try

try {
    // Code that throws exceptions
} catch(e:OverflowException) {
    // Catch a specific exception
} catch(e:Exception) {
    // Catch the generic exceptions
} finally {
    // Execute some cleanup code
}

// Using Strings
String s1;
String s2 = "hello";
s2 += " world";
s1 = s2 + " !!!";

// Using StringBuilder class for performance
StringBuilder s3 = new StringBuilder();
s3.Append("hello");
s3.Append(" world");
s3.Append(" !!!");

' Using Strings
Dim s1, s2 As String
s2 = "hello"
s2 &= " world"
s1 = s2 & " !!!"

' Using StringBuilder class for performance
Dim s3 As New StringBuilder()
s3.Append("hello")
s3.Append(" world")
s3.Append(" !!!")

// Using Strings
var s1 : String;
var s2 : String = "hello";
s2 += " world";
s1 = s2 + " !!!";

// Using StringBuilder class for performance
var s3:StringBuilder = new StringBuilder();
s3.Append("hello");
s3.Append(" world");
s3.Append(" !!!");

void MyButton_Click(Object sender,
                    EventArgs E) {
...
}

Sub MyButton_Click(Sender As Object,
                   E As EventArgs)
...
End Sub

function MyButton_Click(sender : Object,
                        E : EventArgs) {
...
}

// Create a public event
public event EventHandler MyEvent;

// Create a method for firing the event
protected void OnMyEvent(EventArgs e) {
      MyEvent(this, e);
}

' Create a public event
Public Event MyEvent(Sender as Object, E as EventArgs)

' Create a method for firing the event
Protected Sub OnMyEvent(E As EventArgs)
    RaiseEvent MyEvent(Me, E)
End Sub

JScript does not support the creation of events.  JScript can only
consume events by declaring event handler delegates and adding those
delegates to the events of another control.

Control.Change += new EventHandler(this.ChangeEventHandler);
Control.Change -= new EventHandler(this.ChangeEventHandler);

AddHandler Control.Change, AddressOf Me.ChangeEventHandler
RemoveHandler Control.Change, AddressOf Me.ChangeEventHandler

Control.Change += this.ChangeEventHandler;
Control.Change -= this.ChangeEventHandler;

MyObject obj = (MyObject)Session["Some Value"];
IMyObject iObj = obj;

Dim obj As MyObject
Dim iObj As IMyObject
obj = Session("Some Value")
iObj = CType(obj, IMyObject)

var obj : MyObject = MyObject(Session("Some Value"));
var iObj : IMyObject = obj;

int i = 3;
String s = i.ToString();
double d = Double.Parse(s);

Dim i As Integer
Dim s As String
Dim d As Double

i = 3
s = i.ToString()
d = CDbl(s)

' See also CDbl(...), CStr(...), ...

var i : int = 3;
var s : String = i.ToString();
var d : double = Number(s);

using System;

namespace MySpace {

  public class Foo : Bar {

    int x;

    public Foo() { x = 4; }
    public void Add(int x) { this.x += x; }
    override public int GetNum() { return x; }
  }

}

// csc /out:librarycs.dll /t:library
// library.cs

Imports System

Namespace MySpace

  Public Class Foo : Inherits Bar

    Dim x As Integer

    Public Sub New()
      MyBase.New()
      x = 4
    End Sub

    Public Sub Add(x As Integer)
      Me.x = Me.x + x
    End Sub

    Overrides Public Function GetNum() As Integer
       Return x
    End Function

  End Class

End Namespace

' vbc /out:libraryvb.dll /t:library
' library.vb

import System;

package MySpace {

  class Foo extends Bar {

    private var x : int;

    function Foo() { x = 4; }
    function Add(x : int) { this.x += x; }
    override function GetNum() : int { return x; }
  }

}

// jsc /out:libraryjs.dll library.js

public class MyClass : IEnumerable {
 ...

    IEnumerator IEnumerable.GetEnumerator() {
         ...
    }
}

Public Class MyClass : Implements IEnumerable
 ...

    Function IEnumerable_GetEnumerator() As IEnumerator Implements IEnumerable.GetEnumerator
         ...
    End Function
End Class

public class MyClass implements IEnumerable {
 ...

    function IEnumerable.GetEnumerator() : IEnumerator {
         ...
    }
}

using System;

public class ConsoleCS {

  public ConsoleCS() {
    Console.WriteLine("Object Created");
  }

  public static void Main (String[] args) {
    Console.WriteLine("Hello World");
    ConsoleCS ccs = new ConsoleCS();
  }

}

// csc /out:consolecs.exe /t:exe console.cs

Imports System

Public Class ConsoleVB

  Public Sub New()
    MyBase.New()
    Console.WriteLine("Object Created")
  End Sub

  Public Shared Sub Main()
    Console.WriteLine("Hello World")
    Dim cvb As New ConsoleVB
  End Sub

End Class

' vbc /out:consolevb.exe /t:exe console.vb

class ConsoleCS {

  function ConsoleCS() {
    print("Object Created");
  }

  static function Main (args : String[]) {
    print("Hello World");
    var ccs : ConsoleCS = new ConsoleCS();
  }
}

// jsc /out:consolejs.exe /exe console.js

using System;

public class Module {

public static void Main (String[] args) {
  Console.WriteLine("Hello World");
}

}
// csc /out:consolecs.exe /t:exe console.cs

Imports System

Public Module ConsoleVB

  Public Sub Main()
    Console.WriteLine("Hello World")
  End Sub

End Module

' vbc /out:consolevb.exe /t:exe console.vb

print("Hello World");

// jsc /out:consolejs.exe /exe console.js