Practical Approach of Adding, Removing and Inserting Item Using Generic List


Now let's see how to do various types of mechanisms like adding, removing and inserting.

  1. How to Add an item to the generic List<T>?

    /// <summary>
    /// This is static collection used in this tutorials
    ///
    </summary>
    /// <returns></returns>


    private static List<CompanyProduct> AddCollection()

    {

        List<CompanyProduct> list = new List<CompanyProduct>();

        list.Add(new CompanyProduct("MS Word", 1, "Microsoft", new DateTime(2012, 10, 31)));

        list.Add(new CompanyProduct("MS Excel", 2, "Microsoft", new DateTime(2011, 10, 31)));

        list.Add(new CompanyProduct("MS Powerpoint", 3, "Microsoft", new DateTime(2010, 10, 31)));

        list.Add(new CompanyProduct("Visual Studio", 2, "Microsoft", new DateTime(2011, 10, 31)));

        list.Add(new CompanyProduct("Sql Server", 3, "Microsoft", new DateTime(2010, 10, 31)));

        list.Add(new CompanyProduct("Oracle", 4, "Oracle", new DateTime(2011, 10, 31)));

     

        DisplayingList(list, "List of COllection");

     

         return list;

    }
     

  2. How to Add or Append Items to the existing generic List<T>?

    /// <summary>

    /// This is used to add items to collection at once.

    /// </summary>

    private static void AppendingItems()

    {

        List<CompanyProduct> list = new List<CompanyProduct>();

        list.Add(new CompanyProduct("Sharepoint", 6, "Microsoft", new DateTime(2012, 10, 31)));

        list.Add(new CompanyProduct("MS Outlook", 7, "Microsoft", new DateTime(2011, 10, 31)));

     

        List<CompanyProduct> existingItems = AddCollection();

        existingItems.AddRange(list);

     

        //Display all the appended items.

        DisplayingList(existingItems, "Displaying Appending Item at once");

    }
     

  3. How to Add or Append a Collection of items to an existing generic List<T>?

    /// <summary>

    /// This is used to add one by one item.

    /// </summary>

    private static void AppendingItem()

    {

        List<CompanyProduct> existingItems = AddCollection();

        existingItems.Add(new CompanyProduct("Yahoo WebBlog", 4, "Yahoo", new DateTime(2012, 10, 31)));

     

        DisplayingList(existingItems, "Displaying Appending Item one by one");

    }
     

  4. How to Remove an item from the generic List<T>?

    /// <summary>

    /// Removes the specified Single item from the list.

    /// </summary>

    private static void RemoveItem()

    {
        CompanyProduct
    removeSharepoint = new CompanyProduct("Sharepoint", 6, "Microsoft", new DateTime(2012, 10, 31));
       
    CompanyProduct removeOutlook = new CompanyProduct("MS Outlook", 7, "Microsoft", new DateTime(2011, 10, 31)); 

        //Existing Items

        List<CompanyProduct> existingItems = AddCollection(); 

       //It removes the sharepoint product from list.So whatever companyProduct you sends

       // it just remove from the list.

       existingItems.Remove(removeSharepoint);

       existingItems.Remove(removeOutlook);

     

       DisplayingList(existingItems, "Removing Item one by one");

    }
     

  5. How to Remove the specific item from the generic List<T>?

    /// <summary>

    /// Removes the specified item by index.

    /// </summary>

    private static void RemoveSpecificItem()

    {

     

        //Existing Items

        List<CompanyProduct> existingItems = AddCollection();

     

        //It removes the sharepoint product from list.So whatever companyProduct you sends

        // it just remove from the list.

        existingItems.RemoveAt(1); // Removed MS Word

        existingItems.RemoveAt(3); // Removed MS PowerPoint

     

        DisplayingList(existingItems, "Removing Item one by one");

    }
     

  6. How to Remove the range of items from the generic List<T>?

    /// <summary>

    /// This is used to remove the specific range of items

    /// </summary>

    private static void RemoveSpecificRangeOfItems()

    {

         List<CompanyProduct> existingItems = AddCollection();

         //it removes first item from the list.

         existingItems.RemoveRange(1, 1);

     

         //it starts from second element and remove 2nd and 3rd item form the list.

         existingItems.RemoveRange(2, 2);

         DisplayingList(existingItems, "Removed Items");

    }
     

  7. How to Clear items from the generic List<T>?

    /// <summary>

    /// This is used to remove all the elements form the list.

    /// </summary>

    private static void CleareAllItem()

    {

         List<CompanyProduct> existingItems = AddCollection();

         existingItems.Clear();

         Console.WriteLine("count of List=", existingItems.Count);

    }
     

  8. How to Insert an item to the Generic List<T>?

    /// <summary>

    /// This is used to insert item at the last of collection.

    /// </summary>

    private static void InsertItem()

    {

         CompanyProduct addnotepad = new CompanyProduct("Notepad ", 7, "Unknown",

         new DateTime(2011, 10, 31));

     

         //Existing Items

         List<CompanyProduct> existingItems = AddCollection();

     

         //Inserted the norepad product at index 1.

         existingItems.Insert(1, addnotepad);

     

         DisplayingList(existingItems, "Displaying Inserted Item");

    }
     

  9. How to Insert items at a specified range to the Generic List<T>?

    /// <summary>

    /// This is used to insert item at specified range.

    /// </summary>

    private static void InsertRangeItem()

    {

         List<CompanyProduct> list = new List<CompanyProduct>();

         list.Add(new CompanyProduct("LinqPad", 1, "Unknown",

         new DateTime(2012, 10, 31)));

         list.Add(new CompanyProduct("Silverlight", 2, "Microsoft",

         new DateTime(2011, 10, 31)));

     

         //Existing Items

         List<CompanyProduct> existingItems = AddCollection();

     

         //Inserted the norepad product at index 1.

         existingItems.InsertRange(3, list);

     

         DisplayingList(existingItems, "Displaying Inserted Collection");

    }

Note: Download the source and debug the code, it helps to understand the exact operations with the List.

Thanks for reading this article. Have a nice day.