vb.net - VB.NET 生成 1 到 10 之间的唯一 5 个数字

Question

您好，我在 0 和 10 之间有 5 个唯一数字，我正在执行以下操作：

Dim RandomClass As New Random()
Dim RandomNumber As Integer
For counter As Integer = 0 To 5
    RandomNumber = RandomClass.Next(0, 10)
    MsgBox(RandomNumber )
Next

有时它有效，我得到这些数字：“1,7,4,9,3”，但有时我得到一个重复的数字，如：“5,2,3,2,7”

我怎样才能确保每次都有唯一的数字？

谢谢你。

Answer 1

用于记住已经打印出来的数字HashSet(Of Integer)：

Dim RandomClass As New Random()
Dim RememberSet As New HashSet(Of Integer)

Dim RandomNumber As Integer

While RememberSet.Count < 5
    RandomNumber = RandomClass.Next(0, 10)
    If RememberSet.Add(RandomNumber) Then
        MsgBox(RandomNumber)
    End If
End While

Answer 2

只是为了好玩，另一种方法，制作一个从 0 到 10 的整数列表，使用随机生成器在该列表中获取索引，打印该数字并从列表中删除。将随机数的生成保持在限制范围内

Dim numbers = Enumerable.Range(0, 11).ToList()
Dim RandomClass As New Random()
Dim RandomIndex As Integer
For counter As Integer = 1 To 5
    RandomIndex = RandomClass.Next(0, numbers.Count)
    MsgBox(numbers(RandomIndex))
    numbers.RemoveAt(RandomIndex)
Next

Answer 3

我建议添加一个种子，这样随机数就不会重复。

Dim RandomClass As New Random(DateTime.Now.Ticks)
Dim RememberSet As New HashSet(Of Integer)

Dim RandomNumber As Integer

While RememberSet.Count < 5
    RandomNumber = RandomClass.Next(0, 10)
    If RememberSet.Add(RandomNumber) Then
        MsgBox(RandomNumber)
    End If
End While

Answer 4

尝试以下：

 Sub Main()

    Dim a As String() = New String(2) {}
    Dim b As String
    Dim c As Integer = 0
    Dim d As String = " "
    Do
        Console.Clear()
        Console.Write("Enter your name:")
        a(c) = Console.ReadLine()
        c += 1

    Loop Until c = 3
    For Each d In a
        Console.Write(" " & d)
    Next
    Console.ReadLine()