VB.Net - 逻辑/位运算符

下表显示了VB.Net支持的所有逻辑运算符。 假设变量A为布尔值True，变量B为布尔值False，则：

短路运算：一种逻辑运算规则，我们知道与逻辑运算的算法是只要有一个假就能判定为假，或运算符只要有一个为真就能判定为真。短路运算的算法就是建立在这一基础上。
以与运算为例：当两个表达式前一个表达式判定为假时，第二个表达式不会进行计算，直接返回假
这样的计算被称为短路运算，它可以提高逻辑运算的速度（毕竟有一部分情况只需要计算第一个表达式即可）
但是短路运算也有其缺点，就是不够严谨，特别是部分情况下还是需要运算第二个表达式。所以很多语言都有提供短路版本和非短路版本的与运算和或运算。

尝试以下示例来了解VB.Net中提供的所有逻辑/按位运算符：

Module logicalOp

    Sub Main()
        Dim a As Boolean = True
        Dim b As Boolean = True
        Dim c As Integer = 5
        Dim d As Integer = 20
        'logical And, Or and Xor Checking
        If (a And b) Then
            Console.WriteLine("Line 1 - Condition is true")
        End If
        If (a Or b) Then
            Console.WriteLine("Line 2 - Condition is true")
        End If
        If (a Xor b) Then
            Console.WriteLine("Line 3 - Condition is true")
        End If
        'bitwise And, Or and Xor Checking
        If (c And d) Then
            Console.WriteLine("Line 4 - Condition is true")
        End If
        If (c Or d) Then
            Console.WriteLine("Line 5 - Condition is true")
        End If
        If (c Or d) Then
            Console.WriteLine("Line 6 - Condition is true")
        End If
        'Only logical operators
        If (a AndAlso b) Then
            Console.WriteLine("Line 7 - Condition is true")
        End If
        If (a OrElse b) Then
            Console.WriteLine("Line 8 - Condition is true")
        End If

        ' lets change the value of  a and b 
        a = False
        b = True
        If (a And b) Then
            Console.WriteLine("Line 9 - Condition is true")
        Else
            Console.WriteLine("Line 9 - Condition is not true")
        End If
        If (Not (a And b)) Then
            Console.WriteLine("Line 10 - Condition is true")
        End If
        Console.ReadLine()
    End Sub
End Module

当上述代码被编译和执行时，它产生以下结果：

Line 1 - Condition is true
Line 2 - Condition is true
Line 4 - Condition is true
Line 5 - Condition is true
Line 6 - Condition is true
Line 7 - Condition is true
Line 8 - Condition is true
Line 9 - Condition is not true
Line 10 - Condition is true