Part 76 - Working with generic list class and ranges in c#

Suggested Videos 
Part 73 - What is dictionary in c# continued
Part 74 - List collection class in c#
Part 75 - List collection class in c# continued



Please watch Part 74 & 75 before proceeding with this video. In thie video, we will discuss

1. AddRange() - Add() method allows you to add one item at a time to the end of the list, where as AddRange() allows you to add another list of items, to the end of the list.

2. GetRange() - Using an item index, we can retrieve only one item at a time from the list, if you want to get a list of items from the list, then use GetRange() function. This function expects 2 parameters, i.e the start index in the list and the number of elements to return.

3. InsertRange() - Insert() method allows you to insert a single item into the list at a specificed index, where as InsertRange() allows you, to insert another list of items to your list at the specified index.

4. RemoveRange() - Remove() function removes only the first matching item from the list. RemoveAt() function, removes the item at the specified index in the list. RemoveAll() function removes all the items that matches the specified condition. RemoveRange() method removes a range of elements from the list. This function expects 2 parameters, i.e the start index in the list and the number of elements to remove. If you want to remove all the elements from the list without specifying any condition, then use Clear() function.



public class Program
{
    public static void Main()
    {
        // Create Customer Objects
        Customer customer1 = new Customer()
        {
            ID = 101,
            Name = "Mark",
            Salary = 4000,
            Type = "RetailCustomer"
        };

        Customer customer2 = new Customer()
        {
            ID = 102,
            Name = "Pam",
            Salary = 7000,
            Type = "RetailCustomer"
        };

        Customer customer3 = new Customer()
        {
            ID = 103,
            Name = "Rob",
            Salary = 5500,
            Type = "RetailCustomer"
        };

        Customer customer4 = new Customer()
        {
            ID = 104,
            Name = "John",
            Salary = 6500,
            Type = "CorporateCustomer"
        };

        Customer customer5 = new Customer()
        {
            ID = 105,
            Name = "Sam",
            Salary = 3500,
            Type = "CorporateCustomer"
        };

        
        List<Customer> listCustomers = new List<Customer>();
        // Add() method allows you to add one at a time to the end of the list
        listCustomers.Add(customer1);
        listCustomers.Add(customer2);
        listCustomers.Add(customer3);

        List<Customer> listCorporateCustomers = new List<Customer>();
        listCorporateCustomers.Add(customer4);
        listCorporateCustomers.Add(customer5);

        // AddRange() allows you to add another list of items, to the end of the list
        listCustomers.AddRange(listCorporateCustomers);

        foreach (Customer customer in listCustomers)
        {
            Console.WriteLine("ID = {0}, Name = {1}, Salary = {2}, Type = {3}",
                customer.ID, customer.Name, customer.Salary, customer.Type);
        }
        Console.WriteLine("------------------------------------------------------");

        // GetRange() function returns a list of items from the list.
        List<Customer> corporateCustomers = listCustomers.GetRange(3, 2);
        foreach (Customer customer in corporateCustomers)
        {
            Console.WriteLine("ID = {0}, Name = {1}, Salary = {2}, Type = {3}",
                customer.ID, customer.Name, customer.Salary, customer.Type);
        }
        Console.WriteLine("------------------------------------------------------");

        // Remove() function removes only the first matching item from the list.
        listCustomers.Remove(customer1);

        // RemoveAt() function, removes the item at the specified index in the list.
        listCustomers.RemoveAt(0);

        // RemoveAll() function removes all the items that matches the specified condition.
        listCustomers.RemoveAll(x => x.Type == "RetailCustomer");

        foreach (Customer customer in listCustomers)
        {
            Console.WriteLine("ID = {0}, Name = {1}, Salary = {2}, Type = {3}",
                customer.ID, customer.Name, customer.Salary, customer.Type);
        }
        Console.WriteLine("------------------------------------------------------");

        // RemoveRange() method removes a range of elements from the list. 
        // This function expects 2 parameters, i.e the start index in the 
        // list and the number of elements to remove.
        listCustomers.RemoveRange(0, 2);

        // Insert() method allows you to insert a single item at a time into 
        // the list at a specificed index
        listCustomers.Insert(0, customer1);
        listCustomers.Insert(1, customer2);
        listCustomers.Insert(2, customer3);

        // InsertRange() allows you, to insert another list of items to your list at the specified index
        listCustomers.InsertRange(0, listCorporateCustomers);

        foreach (Customer customer in listCustomers)
        {
            Console.WriteLine("ID = {0}, Name = {1}, Salary = {2}, Type = {3}",
                customer.ID, customer.Name, customer.Salary, customer.Type);
        }
        Console.WriteLine("------------------------------------------------------");

        // If you want to remove all the elements from the list without specifying 
        // any condition, then use Clear() function.
        listCustomers.Clear();

        Console.WriteLine(" Total Items in the List = " + listCustomers.Count);
    }
}

public class Customer
{
    public int ID { get; set; }
    public string Name { get; set; }
    public int Salary { get; set; }
    public string Type { get; set; }
}