如何在VB中随机排列数组? [英] how to shuffle array in VB?

问题描述

我正在尝试创建一个应用程序，它将打乱一个字符串数组并生成 2 个完全不同的版本，其中没有元素相互匹配例如，初始数组是 A、B、C、D、E，而混洗后的数组必须是 B、D、E、A、C.

I'm trying to create and application which will shuffle an string array and produce 2 totally different versions where no element will match each other like for example the initial array is A, B, C, D, E than the shuffled array must be B, D, E, A, C.

在我的情况下，当我对它们进行混洗并尝试产生输出时，我会得到混洗的数组，但它们彼此完全相同.似乎最后一个数组中的值覆盖了前一个数组中的值.

In my case when I suffle them and try to produce an output I get shuffled array but they are completely identical to each other. It seems like the values in last array override the values of the previous ones.

我试图保护他们，但我不知道该怎么做.请任何人都可以告诉我我做错了什么吗?

I tried to protect them but I don't know how to do it. Please can anybody give me a hint about what am I doing wrong?

Dim myArray() As String = {"A", "B", "C", "D", "E"} 

这是触发shuffle的按钮代码

This is the code of the button which triggers shuffle

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    RendomOutput1(myArray)
End Sub

结束课程

这是打乱第一个数组的函数:

THis is the function that shuffles first array:

Sub RendomOutput1(ByVal x() As String)


    Dim t As Integer
    Dim Temp As String
    For i As Integer = 0 To x.Count - 1
        Dim rnd As New Random
        t = rnd.Next(0, x.Count - 1)
        Temp = x(t)
        x(t) = x(i)
        x(i) = Temp
    Next

   RandomOutput2(x) 
 End Sub

这是产生另一个数组并打印结果的函数:

This is the function which produces another array and prints the result:

Sub RendomOutput2(ByRef y() As String)
   Dim y1() As String = y' May be I shall lock or somehow protect y1 here?
    'Lock(y1) doesn't work
    Dim t As Integer
    Dim Temp As String
    For i As Integer = 0 To y.Count - 1
        Dim rnd As New Random
        t = rnd.Next(0, y.Count - 1)
        Temp = y(t)
        y(t) = y(i)
        y(i) = Temp
    Next

    For i As Integer = 0 To x.Count - 1
        Label1.Text &= y1(i) & " IS NOT  " & y(i) & vbCrLf
    Next
End Sub

结果数组 y1 和 y 与初始值不同，但彼此相同.有谁知道我怎样才能让他们与众不同.可能锁定 y1 数组或其他东西.提前致谢

IN the result arrays y1 and y are different from initial but identical to each other. Does anybody know how can I make them different. Probably lock y1 array or something. Thank you in advance

推荐答案

此行

Dim y1() As String = y

不创建新数组 - 它创建对现有数组的引用.因此，您将有两个数组引用(y 和 y1)，但只有一个数组(两个引用都指向同一个数组).当您对 y 进行更改时，这些更改通过 y1 可见，因为它们都引用相同的底层数组.

doesn't create a new array - it creates a reference to an existing array. So you'll have two array references (y and y1) but only one array (both references point to the same array). When you make changes to y those changes are visible through y1 because both of them refer to the same underlying array.

您需要的是 2 个不同的数组实例，其中保存的数据是重复的(也就是说，您需要 2 个指向 2 个不同数组的数组引用).那么对一个数组所做的更改不会影响另一个数组.

What you need is 2 distinct array instances where the data held be the arrays are duplicated (that is, you need 2 array references that point to 2 different arrays). Then changes made to one array will not affect the other array.

例如:

' Create new array from the input array
Dim y1() As String = new String(y.Count-1){}

For i As Integer = 0 To y.Count-1
    y1(i) = y(i)
Next i

或者，您也可以克隆数组:

Dim y1() As String = y.Clone()

在幕后，这会导致同样的事情.

Behind the scenes this results in the same thing.

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