CSharp:Hashtable

Le hashtable possono esser paragonate ai Dictionary, sulla rete spesso si opta per quest'ultimi perferibili per prestazioni etc. I Dictionary internamente sono comunque rappresentati come hashtable.
Alcuni link per informazioni sul confronto:

• stackoverflow 1
• stackoverflow 2

Hash table in esempi

Sono vettori\dizionari ottimizzati. Da DotNet perls

Es. 1

using System;
using System.Collections;
 
class Program
{
    static void Main()
    {
	Hashtable hashtable = new Hashtable();
	hashtable[1] = "One";
	hashtable[2] = "Two";
	hashtable[13] = "Thirteen";
 
	foreach (DictionaryEntry entry in hashtable)
	{
	    Console.WriteLine("{0}, {1}", entry.Key, entry.Value);
	}
    }
}

Output:

13, Thirteen
2, Two
1, One

Es. 2

using System;
using System.Collections;
 
class Program
{
    static Hashtable GetHashtable()
    {
	// Create and return new Hashtable.
	Hashtable hashtable = new Hashtable();
	hashtable.Add("Area", 1000);
	hashtable.Add("Perimeter", 55);
	hashtable.Add("Mortgage", 540);
	return hashtable;
    }
 
    static void Main()
    {
	Hashtable hashtable = GetHashtable();
 
	// See if the Hashtable contains this key.
	Console.WriteLine(hashtable.ContainsKey("Perimeter"));
 
	// Test the Contains method. It works the same way.
	Console.WriteLine(hashtable.Contains("Area"));
 
	// Get value of Area with indexer.
	int value = (int)hashtable["Area"];
 
	// Write the value of Area.
	Console.WriteLine(value);
    }
}

Output:

True
True
1000

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C#

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Visual Studio | Dictionary