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  • 哈希表

       Hashtable()为哈希表,可以在保存值的同时保存关键字,便于以后搜索,如存储美国州名的同时存储州的简写,如简写为"CA" ,州名为"California",其有Add,Clear,Clone,CopyTo,ContainsKey等方法:

    /*
      Example11_7.cs illustrates the use of the Hashtable methods
    */
    
    using System;
    using System.Collections;
    
    class Example11_7
    {
    
      public static void Main()
      {
    
        // create a Hashtable object
        Hashtable myHashtable = new Hashtable();
    
        // add elements containing US state abbreviations and state
        // names to myHashtable using the Add() method
        myHashtable.Add("AL", "Alabama");
        myHashtable.Add("CA", "California");
        myHashtable.Add("FL", "Florida");
        myHashtable.Add("NY", "New York");
        myHashtable.Add("WY", "Wyoming");
    
        // display the keys for myHashtable using the Keys property
        foreach (string myKey in myHashtable.Keys)
        {
          Console.WriteLine("myKey = " + myKey);
        }
    
        // display the values for myHashtable using the Values property
        foreach(string myValue in myHashtable.Values)
        {
          Console.WriteLine("myValue = " + myValue);
        }
    
        // use the ContainsKey() method to check if myHashtable
        // contains the key "FL"
        if (myHashtable.ContainsKey("FL"))
        {
          Console.WriteLine("myHashtable contains the key FL");
        }
    
        // use the ContainsValue() method to check if myHashtable
        // contains the value "Florida"
        if (myHashtable.ContainsValue("Florida"))
        {
          Console.WriteLine("myHashtable contains the value Florida");
        }
    
        // use the Remove() method to remove FL from myHashtable
        Console.WriteLine("Removing FL from myHashtable");
        myHashtable.Remove("FL");
    
        // get the number of elements in myHashtable using the Count
        // property
        int count = myHashtable.Count;
    
        // copy the keys from myHashtable into an array using
        // the CopyTo() method and then display the array contents
        Console.WriteLine("Copying keys to myKeys array");
        string[] myKeys = new string[count];
        myHashtable.Keys.CopyTo(myKeys, 0);
        for (int counter = 0; counter < myKeys.Length; counter++)
        {
          Console.WriteLine("myKeys[" + counter + "] = " +
            myKeys[counter]);
        }
    
        // copy the values from myHashtable into an array using
        // the CopyTo() method and then display the array contents
        Console.WriteLine("Copying values to myValues array");
        string[] myValues = new string[count];
        myHashtable.Values.CopyTo(myValues, 0);
        for (int counter = 0; counter < myValues.Length; counter++)
        {
          Console.WriteLine("myValues[" + counter + "] = " +
            myValues[counter]);
        }
    
      }
    
    }
    
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  • 原文地址:https://www.cnblogs.com/djcsch2001/p/2039423.html
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