C# - SPLessons

How to use C# HashTable Class

SPLessons 5 Steps, 3 Clicks
5 Steps - 3 Clicks

How to use C# HashTable Class

How to use C# HashTable Class

Description :

Hi Friends, let me give you a intro about How to use C# HashTable Class. It is a collection with key and value as a pair. Object are organized based on the hash code of the key. It is easy to perform action like Add, Delete, Search, etc. using key as Index of the list.

 

Namespace :

[csharp]
using System.Collections;
[/csharp]

Step1 :

Please open visual studio, right now i have visual studio 2013 i just opened my visual studio and click on new project.

Step2 :

In the new project window please click on templates visual c# and then click on windows  and on the right side panel just click on console application. Please give a name for the console application and click ok button.

Step3 :

If you see the visual studio will gives you a predefined template program  for us.

Step4 :

Lets, Build simple console application to Add, Delete, Find value with key, Find value with value and Display items from HashTable.

Main Method :

[csharp]
class Program
{
public static Hashtable hashtable = new Hashtable();
public static Boolean flag = true;
static void Main(string[] args)
{
while (flag)
{
Console.WriteLine("\n1. Insert \t\t2. Remove \n3. Find value with key \t4. Find value with value\n5. Display\t\t6. Exit");
Console.Write("Please enter your Choice: ");
string choice = Console.ReadLine();
switch (choice)
{
case "1":
hashtable = Insert(hashtable);
break;
case "2":
hashtable = Remove(hashtable);
break;
case "3":
FindValueUsingKey(hashtable);
break;
case "4":
FindValueUsingValue(hashtable);
break;
case "5":
Display(hashtable);
break;
case "6":
flag = false;
break;
default:
Console.WriteLine("Enter correct choice !!");
break;
}
}
}
[/csharp]


Output :


Insert :

[csharp]
private static Hashtable Insert(Hashtable hashtable)
{
Console.Write("Please enter data into HashTable.\nKey : ");
string key = Console.ReadLine();
Console.Write("Value : ");
string value = Console.ReadLine();
hashtable.Add(key, value);
Display(hashtable);
return hashtable;
}
[/csharp]


Output :


Remove :

[csharp]
private static Hashtable Remove(Hashtable hashtable)
{
Console.Write("Please enter data to delete from HashTable.\nKey : ");
string key = Console.ReadLine();
hashtable.Remove(key);
Display(hashtable);
return hashtable;
}
[/csharp]


Output :


Finding Value using Key :

[csharp]
private static void FindValueUsingKey(Hashtable hashtable)
{
Console.Write("Please enter data to find value in HashTable.\nKey : ");
string key = Console.ReadLine();
Boolean flag = hashtable.ContainsKey(key);
if(flag)
{
Console.WriteLine(key + " have a Value in HashTable.");
}
else
{
Console.WriteLine(key + " doesn’t have any Value in HashTable.");
}
}
[/csharp]


Output :


Finding Value using Value :

[csharp]
private static void FindValueUsingValue(Hashtable hashtable)
{
Console.Write("Please enter data to find value in HashTable.\nValue : ");
string value = Console.ReadLine();
Boolean flag = hashtable.ContainsValue(value);
if (flag)
{
Console.WriteLine(value + " is there in HashTable.");
}
else
{
Console.WriteLine(value + " is not there in HashTable.");
}
}
[/csharp]


Output :


Display :

[csharp]
private static void Display(Hashtable hashtable)
{
var item = hashtable.GetEnumerator();
while(item.MoveNext())
{
Console.WriteLine(item.Key + "\t: " + item.Value);
}
}
[/csharp]


Output :

Other Function :

There are many other function which you can try.


Keys :
Gets an ICollection containing the keys in the Hashtable.


Values :
Gets an ICollection containing the values in the Hashtable.


Contains :
Determines whether the Hashtable contains a specific key.


CopyTo :
Returns an Hashtable to an existing one-dimensional Array.


Clear :
Removes all elements from the Hashtable.
etc.


Enjoy to Code..;)

Comments