Empty

The Empty keyword is used to indicate an uninitialized variable value. This is not the same thing as Null.

False

The False keyword has a value equal to 0.

Nothing

The Nothing keyword in VBScript is used to disassociate an object variable from any actual object. Use the Set statement to assign Nothing to an object variable. For example:

Set MyObject = Nothing

Several object variables can refer to the same actual object. When Nothing is assigned to an object variable, that variable no longer refers to any actual object. When several object variables refer to the same object, memory and system resources associated with the object to which the variables refer are released only after all of them have been set to Nothing, either explicitly using Set, or implicitly after the last object variable set to Nothing goes out of scope.

Null

The Null keyword is used to indicate that a variable contains no valid data. This is not the same thing as Empty.

True

The True keyword has a value equal to -1.