C# AND（开发者如何使用）

bool a = true;
bool b = false;

if (a && b)
{
    Console.WriteLine("Both conditions are true!");
}
else
{
    Console.WriteLine("At least one condition is false!");
}

Dim a As Boolean = True
Dim b As Boolean = False

If a AndAlso b Then
	Console.WriteLine("Both conditions are true!")
Else
	Console.WriteLine("At least one condition is false!")
End If

int x = 0;

// The first condition (x != 0) is false, so the second condition (10 / x > 1) is not evaluated.
if (x != 0 && 10 / x > 1)
{
    Console.WriteLine("This won't cause an error.");
}
else
{
    Console.WriteLine("Short-circuit evaluation prevented a divide by zero error!");
}

Dim x As Integer = 0

' The first condition (x != 0) is false, so the second condition (10 / x > 1) is not evaluated.
If x <> 0 AndAlso 10 \ x > 1 Then
	Console.WriteLine("This won't cause an error.")
Else
	Console.WriteLine("Short-circuit evaluation prevented a divide by zero error!")
End If

bool isAdult = true;
bool hasLicense = false;

// Checks if a person is an adult and does not have a license.
if (isAdult && !hasLicense)
{
    Console.WriteLine("You're an adult but don't have a driving license!");
}

Dim isAdult As Boolean = True
Dim hasLicense As Boolean = False

' Checks if a person is an adult and does not have a license.
If isAdult AndAlso Not hasLicense Then
	Console.WriteLine("You're an adult but don't have a driving license!")
End If

class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
}

Person person1 = new Person { Name = "Alice", Age = 30 };
Person person2 = new Person { Name = "Bob", Age = 25 };

// Check if both persons are older than 20.
if (person1.Age > 20 && person2.Age > 20)
{
    Console.WriteLine("Both persons are older than 20!");
}

Friend Class Person
	Public Property Name() As String
	Public Property Age() As Integer
End Class

Private person1 As New Person With {
	.Name = "Alice",
	.Age = 30
}
Private person2 As New Person With {
	.Name = "Bob",
	.Age = 25
}

' Check if both persons are older than 20.
If person1.Age > 20 AndAlso person2.Age > 20 Then
	Console.WriteLine("Both persons are older than 20!")
End If

int score = 85;
bool isFinalExam = true;

// Check if the score is within the B range and if it’s the final exam.
if ((score > 80 && score < 90) && isFinalExam)
{
    Console.WriteLine("You got a B in the final exam!");
}

Dim score As Integer = 85
Dim isFinalExam As Boolean = True

' Check if the score is within the B range and if it's the final exam.
If (score > 80 AndAlso score < 90) AndAlso isFinalExam Then
	Console.WriteLine("You got a B in the final exam!")
End If