Question

所以我试图在vb.net中使用三元运算符来运行一个石头剪刀游戏，但无论我如何设置它，我得到错误的结果（继续输出相同的结果，无论如何实际结果应该是IE，R vs P =输，R vs S =输，R vs R输=

我最初尝试使用结果/绘制bool作为占位符，在结尾显示结果，并在紧跟在IIF之后的ifs中添加了一个退出开关但仍然会导致循环不更改结果。

Public Class Form1
    Const ROCK As Integer = 1
    Const PAPER As Integer = 2
    Const SCISSORS As Integer = 3
    Dim computerThrow As Integer
    Dim comThrow As String = "Rock"
    Dim wins As Integer
    Dim losses As Integer
    Dim draws As Integer
    Dim outcome As Boolean = True
    Dim draw As Boolean = True

    'Spent two days debugging, kept getting more broken. hmm
    Private Sub btnThrow_Click(sender As Object, e As EventArgs) Handles btnThrow.Click

        'Generate computer throw
        Randomize()
        computerThrow = Int(3 * Rnd() + 1)

        'Select case block
        Select Case computerThrow
            Case ROCK
                comThrow = "rock"
                IIf(Me.radRock.Checked = True, draw = True, 1 = 1) 'Ternarys to decide outcome/draw
                If draw = True Then 'If to decide whether to exit or not
                    Me.lblWinner.Text = "Computer throws " + comThrow + ", it's a draw!"
                    draws = draws + 1
                End If
                IIf(Me.radPaper.Checked = True, outcome = True, 1 = 1)
                If outcome = True Then
                    Me.lblWinner.Text = "Computer throws " + comThrow + ", you win!"
                    wins = wins + 1
                End If
                IIf(Me.radScissors.Checked = True, outcome = False, 1 = 1)
                If outcome = False And draw = False Then
                    Me.lblWinner.Text = "Computer throws " + comThrow + ", you lose!"
                    losses = losses + 1
                End If
            Case PAPER
                comThrow = "paper"
                IIf(Me.radRock.Checked = True, outcome = False, 1 = 1)
                If outcome = False And draw = False Then
                    Me.lblWinner.Text = "Computer throws " + comThrow + ", you lose!"
                    losses = losses + 1
                End If
                IIf(Me.radPaper.Checked = True, draw = True, 1 = 1)
                If draw = True Then
                    Me.lblWinner.Text = "Computer throws " + comThrow + ", it's a draw!"
                    draws = draws + 1
                End If
                IIf(Me.radScissors.Checked = True, outcome = True, 1 = 1)
                If outcome = True Then
                    Me.lblWinner.Text = "Computer throws " + comThrow + ", you win!"
                    wins = wins + 1
                End If
            Case SCISSORS
                comThrow = "scissors"
                IIf(Me.radRock.Checked = True, outcome = True, 1 = 1)
                If outcome = True Then
                    Me.lblWinner.Text = "Computer throws " + comThrow + ", you win!"
                    wins = wins + 1
                End If
                IIf(Me.radPaper.Checked = True, outcome = False, 1 = 1)
                If outcome = False And draw = False Then
                    Me.lblWinner.Text = "Computer throws " + comThrow + ", you lose!"
                    losses = losses + 1
                End If
                IIf(Me.radScissors.Checked = True, draw = True, 1 = 1)
                If draw = True Then
                    Me.lblWinner.Text = "Computer throws " + comThrow + ", it's a draw!"
                    draws = draws + 1
                End If
        End Select

        Me.lblResults.Text = "wins: " + wins.ToString() + " Lose: " + losses.ToString() + " draws: " + draws.ToString()

    End Sub
End Class

Answer 1

IIF不是VB.NET中的三元运算符。 IIF is a function评估真实部分和虚假部分。这意味着，无论选中复选框的状态如何，都会始终执行IIF函数的真实部分，因此您始终将变量赋值为true或false。

相反，VB.NET中的conditional ternary operator是 If（表达式，true部分，false部分），它使用shortcircuit evaluation来选择表达式值。因此，您应该以这种方式重写代码

  draw = If(Me.radRock.Checked, True, False)
  If draw Then 
     ....

但此时你可以简单地写一下

  draw = Me.radRock.Checked
  If draw Then 
     ....

或

  outcome = Not Me.radRock.Checked
  ....

Rock Paper Scissors IIF但IIF并没有改变const命名结果的值

1 个答案: