Understand Dictionary and IDictionary in C#

Understand Dictionary and IDictionary in C#

In this article we will try to learn Dictionary and IDictinary in C# programming language. Both belong to collection class in .NET class library. They store data in Key and Value pair.

Dictionary class in C#

As mentioned earlier data is stored in key value pair. It takes any type as key and value. In visual studio we can check it.

In below example we will create simple dictionary with integer as key and string data as value. Have a look on below code.

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;
namespace Client
{
    class Program
    {
        static void Main(string[] args)
        {
            //Understand Dictinary
            Dictionary<int, string> Name = new Dictionary<int, string>();
            Name.Add(1, "sourav");
            Name.Add(2, "Ram");
            Name.Add(3, "shyam");
            foreach(String name in Name.Values)
            {
                Console.WriteLine(name);
            }
    
            Console.ReadLine();
        }
    }
}

Here is output.

Remove item from Dictionary

We can remove any item by specifying it’s key value. In this example we will use Remove() method to remove one item from Dictionary collection.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;
namespace Client
{
    class Program
    {
        static void Main(string[] args)
        {
            //Understand Dictinary
            Dictionary<int, string> Name = new Dictionary<int, string>();
            Name.Add(1, "sourav");
            Name.Add(2, "Ram");
            Name.Add(3, "shyam");
 
            //Remove Value at particular Index
            Name.Remove(2);
            foreach(String name in Name.Values)
            {
                Console.WriteLine(name);
            }
    
            Console.ReadLine();
        }
    }
}

Output is like below.

Understand IDictionary interface

IDictionary is interface from where we can instantiate Dictionary class.  Have a look on below example.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;
namespace Client
{
    class Program
    {
        static void Main(string[] args)
        {
            //Understand IDictinary
            IDictionary<string, string> dis = new Dictionary<string, string>();
            dis.Add("Sourav", "Kayal");
            dis.Add("Ram", "Chandra");
 
            Console.WriteLine("Surname of
sourave is:- " +  dis["Sourav"]);
            Console.ReadLine();
        }
    }
}

Output:-

Like Dictionary, we can use all methods in IDictionary also. Here is another example.

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;
namespace Client
{
    class Program
    {
        static void Main(string[] args)
        {
            //Understand IDictinary
            IDictionary<int, string> student = new Dictionary<int, string>();
            student.Add(1,"Sourav");
            student.Add(2, "Ram");
            student.Add(3, "Shyam");
 
            student.Remove(2);
            Console.WriteLine("Number of
Student:- " + student.Count);
            foreach (string name in student.Values)
            {
                Console.WriteLine(name);
            }
            Console.ReadLine();
        }
    }
}

Output is given below.

Conclusion:-