如何在VB.net中使用Dictionary? [英] How to use Dictionary in VB.net?

问题描述

我已经编写了此功能，可以自动将字符串数组中的不同值的性别正确地校正为M或F.它工作正常，但我的经理告诉我使用字典，他说字典效率更高.但是我不知道.任何人都想帮助我了解如何做到这一点?谢谢.

 公共功能AutoGender(ByVal dt作为数据表)作为数据表性别暗淡为String ="Dim Mkeywords()As String = {男孩"，男孩"，男性"，男人"，"m"，男人"，男人"}Dim Fkeywords()As String = {女孩"，女孩"，女性"，女人"，"f"，妇女"，小鸡"}昏暗的行作为DataRow对于dt.Rows中的每一行如果Mkeywords.Contains(row("Gender").ToString.ToLower)然后性别="M"row("Gender")=性别ElseIf Fkeywords.Contains(row("Gender").ToString.ToLower)然后性别="F"row("Gender")=性别万一下一个返回dt结束功能 

解决方案

下面是一个示例，您可以如何实现 Dictionary(Of String，String)来查找此同义词是否已知:

 作为字典(字符串，字符串)=的新字典(字符串，字符串)共享的GenderSynonyms{{"boy"，"M"}，{"boys"，"M"}，{"male"，"M"}，{"man"，"M"}，{"m"，"M"}，{"men"，"M"}，{"guy"，"M"}，{"girl"，"F"}，{"girls"，"F"}，{"female"，"F"}，{"woman"，"F"}，{"f"，"F"}，{妇女"，"F"}，{小鸡"，"F"}}公共功能AutoGender(ByVal dt作为数据表)作为数据表如果dt.Columns.Contains("Gender")然后对于每行作为dt.Rows中的DataRow昏暗的oldGender = row.Field(Of String)("Gender").ToLower将newGender变暗为String = String.Empty如果GenderSynonyms.TryGetValue(oldGender，newGender)然后row.SetField("Gender"，newGender)万一下一个万一返回dt结束功能 

请注意，我已经使用集合初始化程序来填充词典，这是使用文字初始化集合的便捷方法.您也可以使用 添加方法.

编辑:另一种更为简洁的方法是使用两个 HashSet(Of String) ，一个用于男性同义词，一个用于女性同义词:

 共享的maleSynonyms作为新的HashSet(Of String)来自{男孩"，男孩"，男性"，男人"，"m"，男人"，男人"}共享femaleSynonyms作为新的HashSet(Of String)From{女孩"，女孩"，女性"，女人"，"f"，妇女"，小鸡"}公共功能AutoGender(ByVal dt作为数据表)作为数据表如果dt.Columns.Contains("Gender")然后对于每行作为dt.Rows中的DataRow昏暗的oldGender = row.Field(Of String)("Gender").ToLower将newGender变暗为String = String.Empty如果maleSynonyms.Contains(oldGender)然后row.SetField("Gender"，"M")否则如果是女性同义词.包含(oldGender)然后row.SetField("Gender"，"F")万一下一个万一返回dt结束功能 

HashSet 也必须是唯一的，因此它不能包含重复的 Strings (例如 Dictionary 中的键)，但不是键值对，但只有一组.

I have written this function to auto correct gender to M or F from different values in a string array. It works fine but my manager told me to use Dictionary which he said is more efficient. But I have no idea. Anyone like to help me to understand how this can be done ? Thanks.

    Public Function AutoGender(ByVal dt As DataTable) As DataTable        

    Dim Gender As String = ""
    Dim Mkeywords() As String = {"boy", "boys", "male", "man", "m", "men", "guy"}
    Dim Fkeywords() As String = {"girl", "girls", "female", "woman", "f", "women", "chick"}
    Dim row As DataRow
        For Each row In dt.Rows
            If Mkeywords.Contains(row("Gender").ToString.ToLower) Then
                Gender = "M"
                row("Gender") = Gender
            ElseIf Fkeywords.Contains(row("Gender").ToString.ToLower) Then
                Gender = "F"
                row("Gender") = Gender
            End If
        Next
    Return dt

    End Function

解决方案

Here is an example how you could implement the Dictionary(Of String, String) to lookup whether this synonym is known or not:

Shared GenderSynonyms As Dictionary(Of String, String) = New Dictionary(Of String, String) From
    {{"boy", "M"}, {"boys", "M"}, {"male", "M"}, {"man", "M"}, {"m", "M"}, {"men", "M"}, {"guy", "M"},
     {"girl", "F"}, {"girls", "F"}, {"female", "F"}, {"woman", "F"}, {"f", "F"}, {"women", "F"}, {"chick", "F"}}

Public Function AutoGender(ByVal dt As DataTable) As DataTable
    If dt.Columns.Contains("Gender") Then
        For Each row As DataRow In dt.Rows
            Dim oldGender = row.Field(Of String)("Gender").ToLower
            Dim newGender As String = String.Empty
            If GenderSynonyms.TryGetValue(oldGender, newGender) Then
                row.SetField("Gender", newGender)
            End If
        Next
    End If
    Return dt
End Function

Note that i've used the collection initializer to fill the Dictionary that is a convenient way to use literals to initialize collections. You could also use the Add method.

Edit: Just another approach that might be more concise is using two HashSet(Of String), one for the male synonyms and one for the female:

Shared maleSynonyms As New HashSet(Of String) From
    {"boy", "boys", "male", "man", "m", "men", "guy"}
Shared femaleSynonyms As New HashSet(Of String) From
    {"girl", "girls", "female", "woman", "f", "women", "chick"}

Public Function AutoGender(ByVal dt As DataTable) As DataTable
    If dt.Columns.Contains("Gender") Then
        For Each row As DataRow In dt.Rows
            Dim oldGender = row.Field(Of String)("Gender").ToLower
            Dim newGender As String = String.Empty
            If maleSynonyms.Contains(oldGender) Then
                row.SetField("Gender", "M")
            ElseIf femaleSynonyms.Contains(oldGender) Then
                row.SetField("Gender", "F")
            End If
        Next
    End If
    Return dt
End Function

A HashSet must also be unique, so it cannot contain duplicate Strings (like the key in the Dictionary), but it's not a key-value pair but only a set.

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