Information.IsNothing(Object) Information.IsNothing(Object) Information.IsNothing(Object) Information.IsNothing(Object) Method

Definition

Returns a Boolean value indicating whether an expression has no object assigned to it.

public:
 static bool IsNothing(System::Object ^ Expression);
public static bool IsNothing (object Expression);
static member IsNothing : obj -> bool
Public Function IsNothing (Expression As Object) As Boolean

Parameters

Expression
Object Object Object Object

Required. Object expression.

Returns

Returns a Boolean value indicating whether an expression has no object assigned to it.

Examples

The following example uses the IsNothing function to determine if an object variable is associated with any object instance.

Dim testVar As Object
' No instance has been assigned to variable testVar yet.
Dim testCheck As Boolean
' The following call returns True.
testCheck = IsNothing(testVar)
' Assign a string instance to variable testVar.
testVar = "ABCDEF"
' The following call returns False.
testCheck = IsNothing(testVar)
' Disassociate variable testVar from any instance.
testVar = Nothing
' The following call returns True.
testCheck = IsNothing(testVar)

Remarks

IsNothing returns True if the expression represents an object variable that currently has no object assigned to it; otherwise, it returns False.

IsNothing is intended to work on reference types. A value type cannot hold a value of and reverts to its default value if you assign Nothing to it. If you supply a value type in Expression, IsNothing always returns False.

Applies to

See Also