Question

初学者，请耐心等待，我提前为任何错误道歉。这是一些功课，我遇到了一些麻烦。

总体目标：使用循环语句输出字符串中的特定字符数。例如，用户想要在“为什么鸡过马路？”中找到多少“我”，答案应该是2。

1）表单/ gui有1个MultiLine文本框和1个标题为“Search”的按钮

2）用户在文本框中输入/复制/粘贴文本，单击“搜索”按钮

3）搜索按钮打开一个InputBox，用户将在文本框中键入要搜索的字符，然后按“确定”

4）（我真的需要帮助）使用循环语句，程序搜索并计算文本输入输入框<的次数/ strong>，出现在 MultiLine文本框内的文字中，然后，显示字符在“messagebox.show”中显示的次数

到目前为止我所拥有的一切

Private Sub Search_btn_Click(sender As System.Object, e As System.EventArgs) Handles Search_btn.Click Dim counterInt As Integer = 0 Dim charInputStr As String charInputStr = CStr(InputBox("Enter Search Characters", "Search"))

Answer 1

我会使用String.IndexOf(string, int)方法来获取它。简单的概念示例：

Dim input As String = "Test input string for Test and Testing the Test"
Dim search As String = "Test"

Dim count As Integer = -1
Dim index As Integer = 0

Do
    index = input.IndexOf(search, index) + 1
    count += 1
Loop While index > 0

由于count循环使用，

-1初始化为do-while - 即使输入字符串中没有出现模式，也会将其设置为0。

Answer 2

概念： Increment count，直到input包含特定的search字符串。如果contains字符串为search，则replace首次出现string.empty（在String.contains()中，搜索从其first index开始，即0）

 Dim input As String = "Test input string for Test and Testing the Test"
 Dim search As String = "T"
 Dim count As Integer = 0

 While input.Contains(search) : input = New Regex(search).Replace(input, String.Empty, 1) : count += 1 : End While

 MsgBox(count)

修改

另一种解决方案：

Dim Input As String = "Test input string for Test and Testing the Test" Dim Search As String = "Test" MsgBox((Input.Length - Input.Replace(Search, String.Empty).Length) / Search.Length)

Answer 3

试用此代码

 Dim input As String = "Test input string for Test and Testing the Test"
        Dim search() As String = {"Te"}

        MsgBox(input.Split(input.Split(search, StringSplitOptions.None), StringSplitOptions.RemoveEmptyEntries).Count)

Answer 4

尝试此代码....未经测试但我知道我的vb：）

    Function lol(ByVal YourLine As String, ByVal YourSearch As String)
    Dim num As Integer = 0
    Dim y = YourLine.ToCharArray
    Dim z = y.Count
    Dim x = 0
    Do
        Dim l = y(x)
        If l = YourSearch Then
            num = num + 1
        End If
        x = x + 1
    Loop While x < z

    Return num
End Function

它是一个使用自己的计数器的函数...对于字符串中的每个字符，它将检查该字符是否是您设置的字符（YourSearch），然后它将返回它找到的项目数。所以在你的情况下，它会返回2，因为你的行中有两个我。

希望这有帮助！

修改

这仅适用于搜索单个字符而不是单词
的情况

Answer 5

你可以尝试这样的事情：

Dim sText As String = TextBox1.Text
Dim searchChars() As Char = New Char() {"i"c, "a"c, "x"c}
Dim index, iCont As Integer 

index = sText.IndexOfAny(searchChars)

While index >= 0 Then
    iCont += 1
    index = sText.IndexOfAny(searchChars, index + 1)
End While

Messagebox.Show("Characters found " & iCont & " times in text")

如果您想搜索单词和每个单词出现的时间，请尝试以下方法：

Dim text As String = TextBox1.Text
Dim wordsToSearch() As String = New String() {"Hello", "World", "foo"}
Dim words As New List(Of String)()
Dim findings As Dictionary(Of String, List(Of Integer))

'Dividing into words
words.AddRange(text.Split(New String() {" ", Environment.NewLine()}, StringSplitOptions.RemoveEmptyEntries))

findings = SearchWords(words, wordsToSearch)
Console.WriteLine("Number of 'foo': " & findings("foo").Count)

使用此功能：

Private Function SearchWords(ByVal allWords As List(Of String), ByVal wordsToSearch() As String) As Dictionary(Of String, List(Of Integer))
    Dim dResult As New Dictionary(Of String, List(Of Integer))()
    Dim i As Integer = 0

    For Each s As String In wordsToSearch
        dResult.Add(s, New List(Of Integer))

        While i >= 0 AndAlso i < allWords.Count
            i = allWords.IndexOf(s, i)
            If i >= 0 Then dResult(s).Add(i)
            i += 1
        End While
    Next

    Return dResult
End Function

您不仅会有出现次数，还会有文件中的索引位置，可以轻松地在字典中分组。

如何创建一个循环语句来查找字符串中的特定字符数？

5 个答案: