VB.Net Syntax

And


If (oMyObject Is Nothing) And (bUpdate = False) Then 
End If

AndAlso

Performs short-circuiting logical.
A logical operation is said to be short-circuiting if the compiled code can bypass the evaluation of one expression depending on the result of another expression.
This means if the first expression is False the expression returns False and does not evaluated the second expression.

If (oMyObject Is Nothing) AndAlso (oMyObject.Property = True) Then 
End If

Expression	Returned	Notes
True AndAlso True	True
True AndAlso False	False
False AndAlso True	False	True is not evaluated
False AndAlso False	False	False is not evaluated
Not (True AndAlso True)	False
Not (True AndAlso False)	True
Not (False AndAlso True)	True
Not (False AndAlso False)	True

Or

If (oMyObject Is Nothing) Or (sFullName = "Steven") Then 
End If

OrElse

Performs short-circuiting inclusive logical.
A logical operation is said to be short-circuiting if the compiled code can bypass the evaluation of one expression depending on the result of another expression.
This means if the first expression is True the expression returns False and does not evaluated the second expression.

If (oMyObject Is Nothing) OrElse (sFullName = "Steven") Then 
End If

Expression	Returned	Notes
True OrElse True	True	True is not evaluated
True OrElse False	True	False is not evaluated
False OrElse True	True
False OrElse False	False
Not (True OrElse True)	False
Not (True OrElse False)	False
Not (False OrElse True)	False
Not (False OrElse False)	True

Xor

If (oMyObject Is Nothing) Xor (sFullName = "Steven") Then 
End If

Expression	Returned	Notes
True Xor True	True
True Xor False
False Xor True
False Xor False
Not (True Xor True)
Not (True Xor False)
Not (False Xor True)
Not (False Xor False)