在Visual Basic中創建字符串的索引

Question

如何搜索字符串以創建每次出現的字符串的索引？

例如：

“三只瞎老鼠。三只瞎老鼠。看看它們如何運轉！看看它們如何運轉！”

每當“ ee”開始時，我需要創建一個索引。

Answer 1

您也可以使用Regex進行搜索。

    Dim test = "Three blind mice. Three blind mice. See how they run! See how they run!"
    Dim search As String = "ee"
    Dim indexes As New List(Of Integer)

    For Each m As Match In Regex.Matches(test, search)
        indexes.Add(m.Index)
    Next

Answer 2

string.IndexOf有一個重載，它允許掃描字符串以搜索子字符串

Dim test = "Three blind mice. Three blind mice. See how they run! See how they run!"
Dim indexes = new List(Of Integer)()
Dim pos = -1
while(true)
    pos = test.IndexOf("ee", pos + 1)
    if pos >= 0 then
        indexes.Add(pos)
        pos += 1
    Else
        Exit While
    End if
End While

For each i in indexes
    Console.WriteLine(i)
Next

只是為了好玩，另一個完全不使用IndexOf的版本

Sub Main()
    Dim test = "Three blind mice. Three blind mice. See how they run! See how they run!"
    Dim targetValue = "mice"
    Dim indexes() = AllIndexOf(test, targetValue)
    for each i in indexes
       Console.WriteLine(i)
    Next
End Sub    



Function AllIndexOf(source as string, search as string) as Integer()
    Dim positions = new List(Of Integer)()
    for i = 0 to source.Length-1

        Dim y = i
        Dim x = 0
        while(x < search.Length And y+x < source.Length)

           Dim c = source(y+x)
           if c <> search(x) then
                Exit While
            End If
           x +=1
        End While
        if x = search.Length Then
            positions.Add(y)
        End If
    Next
    return positions.ToArray()
End Function

Answer 3

僅此而已的另一種解決方案！

Dim test = "Three blind mice. Three blind mice. See how they run! See how they run!"
Dim search As String = "ee"
Dim indexes As New List(Of Integer)
Dim i As Integer = test.IndexOf(search)
Do While (i <> -1)
    indexes.Add(i)
    i = test.IndexOf(search, i + 1)
Loop