This blog defines the logical operators in
VB.NET.
Logical Operator
The logical operators compare Boolean
expressions and return a Boolean result. In short, logical operators are
expressions which return a true or false result over a conditional expression.
And— The And operation returns the True if both operands are True, False
otherwise where you treat 0 as False and 1 as True.
Not— Reverses the logical value of its operand, from True to False and
False to True, for bitwise operations, turns 0 into 1 and 1 into 0.
Or— The Or operation returns the True if either operand is True, False
otherwise. where you treat 0 as False and 1 as True.
Xor— Operator performs an exclusive-Or operation True if either operand,
but not both, is True, and False otherwise where you treat 0 as False and 1 as
True.
AndAlso— Operator A "short circuited" And operator; if the first operand
is False, the second operand is not tested.
OrElse— Operator A "short circuited" Or operator, if the first operand is
True, the second is not tested.
For example
Module
Module1
Dim a As
Integer = 15
Dim b As
Integer = 45
Dim gt As
Integer
Sub Main()
If a > b And
check(a) Then
End If
If a > b AndAlso
check(a) Then
End If
If a < b Or
check(a) Then
End If
If a < b OrElse
check(a) Then
End If
End Sub
Function check(ByVal
checkValue As Integer)
As Boolean
If checkValue > 20 Then
MsgBox(CStr(checkValue)
& " is not a valid value.")
Return False
Else
gt +=
checkValue
Return True
End If
End Function
End
Module