Question

给出单词列表......

Word Word Base Ball Ball Apple Cardinal

我如何去除所有出现的“Word”和“Ball”？我做了一些研究并找到了list.RemoveAll函数。我对如何在字符串列表上实现它感到困惑。将列表转换为数组会更好吗？

Public Function getListOfWords() As String()
    listOfWords.RemoveAll("the")
    Dim arrayA() As String = listOfWords.ToArray
    Return arrayA
End Function

Answer 1

这是你可以在List（Of String）上使用RemoveAll的方法

Dim words = New List(Of String) From { "Word","Word","Base","Ball","Ball","Apple","Cardinal"}
Dim wordsRemoved = words.RemoveAll(Function(s) s = "Word" OrElse s = "Ball")
Console.WriteLine(wordsRemoved)
For Each s in words
   Console.WriteLine(s)
Next

在此上下文中，RemoveAll需要一个接收字符串并返回布尔值（A Predicate(Of T)）的函数。函数通过重复调用逐个接收序列中包含的元素，并返回true以删除元素，或者返回false以保留元素

Answer 2

我知道它的回答和接受。但就可扩展性而言，bool谓词似乎有点硬编码，即如果你要删除的单词是＆＃34; Word＆＃34;，＆＃34; Ball＆＃34;，＆＃34; Apple＆＃ 34 ;?现在必须在代码中更改谓词。我想你可以在谓词中聚合代码，但现在事情变得愚蠢了。

您可能还认为问题是需要LEFT OUTER JOIN来解决它，这将接受排除列表中的任意数量的元素。这是一个你可以使用的功能

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<link href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/js/bootstrap.min.js"></script>

<form class="form-horizontal" id="formTest">
  <div class="row">
    <div class="col-xs-6">
      <div class="form-group">
        <label for="lblFirstName" class="control-label col-xs-4">First Name</label>
        <div class="col-xs-8">
          <input type="textbox" class="form-control" />
        </div>
      </div>
    </div>
    <div class="col-xs-6">
      <div class="form-group">
        <label for="lblLastname" class="control-label col-xs-4">Last Name</label>
        <div class="col-xs-8">
          <input type="textbox" class="form-control" />
        </div>
      </div>
    </div>
  </div>
  <div class="row">
    <div class="col-xs-12">
      <div class="form-group">
        <label for="lblComments" class="control-label col-xs-2">Comments</label>
        <div class="col-xs-10">
          <textarea type="textbox" id="Comments" class="form-control"></textarea>
        </div>
      </div>
    </div>
  </div>
</form>

现在，您可以在任何数量的列表中包含两个集合而不是两个bool谓词，并调用函数

Public Function getListOfWords(words As IEnumerable(Of String),
                               wordsToRemove As IEnumerable(Of String)) As String()

    Dim wordsRemoved = From word In words
                       Group Join wordToRemove In wordsToRemove
                           On word Equals wordToRemove Into Group
                       From g In Group.DefaultIfEmpty
                       Where g = ""
                       Select word

    Return wordsRemoved.ToArray()
End Function

Answer 3

假设重复一个接一个：

Dim s = "Word Word Base Ball Ball Apple Cardinal"
Dim pattern = "(?i)(?'word'[a-z]+)(\s+\k'word')"
Dim s2 = Regex.Replace(s, pattern, "${word}")

从列表中删除Word的所有出现次数

3 个答案: