santosh asp.net tutorial

using System;
using System.Collections.Generic;

class CollectionDemo
{
    public CollectionDemo()
    {
        Console.WriteLine("This is Collection Demo::\n");
    }
    public void Show()
    {
        // Create Customer Objects
        Customer customer1 = new Customer()
        {
            ID = 101,
            Name = "Santosh kumar singh",
            Salary = 10000
        };

        Customer customer2 = new Customer()
        {
            ID = 102,
            Name = "Reena kumari",
            Salary = 17000
        };

        Customer customer3 = new Customer()
        {
            ID = 104,
            Name = "Pragya kumari",
            Salary = 95000
        };

        Customer[] arrayCustomers = new Customer[2];
        arrayCustomers[0] = customer1;
        arrayCustomers[1] = customer2;
        // The following line will throw an exception, Index was outside the bounds of the array. 
        // This is because, arrays does not grow in size automatically.
        // arrayCustomers[2] = customer3;

        // Create a List of Customers. Here, we have set the size to 2. But when I add a third 
        // element the list size will automatically grow and we will not get an exception.
        List<Customer> listCustomers = new List<Customer>(2);
        // To add an element to the list, use Add() method.
        listCustomers.Add(customer1);
        listCustomers.Add(customer2);
        // Adding an element beyond the initial capacity of the list will not throw an exception.
        listCustomers.Add(customer3);

        // Items can be retrieved from the list by index. The following code will 
        // retrieve the first item from the list. List index is ZERO based.
        Customer cust = listCustomers[0];
        Console.WriteLine("ID = {0}, Name = {1}, Salary = {2}",
                 cust.ID, cust.Name, cust.Salary);
        Console.WriteLine("------------------------------------------------");

        // foreach or for loop can be used to iterate thru all the items in the list
        // Using for loop
        for (int i = 0; i < listCustomers.Count; i++)
        {
            Customer customer = listCustomers[i];
            Console.WriteLine("ID = {0}, Name = {1}, Salary = {2}",
                     customer.ID, customer.Name, customer.Salary);
        }
        Console.WriteLine("------------------------------------------------");

        // Using foreach loop
        foreach (Customer c in listCustomers)
        {
            Console.WriteLine("ID = {0}, Name = {1}, Salary = {2}", c.ID, c.Name, c.Salary);
        }
        Console.WriteLine("------------------------------------------------");

        // All generic collection classes including List are strongly typed. This means 
        // if you have created a List of type Customer, only objects of type Customer 
        // can be added to the list. If you try to add an object of different type you would 
        // get a compiler error. The following line will raise a compiler error.
        // listCustomers.Add("This will not compile");

        // If you want to insert an item at a specific index location of the list, use Insert() method. 
        // The following line will insert customer3 object at index location 1.
        listCustomers.Insert(1, customer3);
        Console.WriteLine("ID = {0}, Name = {1}, Salary = {2}",
               listCustomers[1].ID, listCustomers[1].Name, listCustomers[1].Salary);
        Console.WriteLine("------------------------------------------------");

        // To get the index of specific item in the list use Indexof() method
        Console.WriteLine("Index of Customer3 object in the List = " +
                listCustomers.IndexOf(customer3));
        Console.WriteLine("------------------------------------------------");
    }
}


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

class TestCollection
{
    static void Main(string[] args)
    {

        CollectionDemo objCollection = new CollectionDemo();
        objCollection.Show();
        Console.ReadLine();
    }
}

  

using System;
using System.Collections.Generic;
using System.Linq;

class CollectionDemoMethod
{
    public CollectionDemoMethod()
    {
        Console.WriteLine("This is collection methods demo::\n");
    }

    public void Show()
    {
          // Create Customer Objects
        Customer customer1 = new Customer()
        {
            ID = 101,
            Name = "Santosh kumar singh",
            Salary = 3000
        };

        Customer customer2 = new Customer()
        {
            ID = 102,
            Name = "Reena kumari",
            Salary = 20000
        };

        Customer customer3 = new Customer()
        {
            ID = 104,
            Name = "Manpreet kaur",
            Salary = 5200
        };

        Customer[] arrayCustomers = new Customer[3];
        arrayCustomers[0] = customer1;
        arrayCustomers[1] = customer2;
        arrayCustomers[2] = customer3;

        // To convert an array to a List, use ToList() method
        List<Customer> listCustomers = arrayCustomers.ToList();
        foreach (Customer c in listCustomers)
        {
            Console.WriteLine("ID = {0}, Name = {1}, Salary = {2}", c.ID, c.Name, c.Salary);
        }
        Console.WriteLine("------------------------------------------------------");

        // To convert a List to an array, use ToLArray() method
        Customer[] arrayAllCustomers = listCustomers.ToArray();
        foreach (Customer c in arrayAllCustomers)
        {
            Console.WriteLine("ID = {0}, Name = {1}, Salary = {2}", c.ID, c.Name, c.Salary);
        }
        Console.WriteLine("------------------------------------------------------");

        // To convert a List to a Dictionary use ToDictionary() method
        Dictionary<int, Customer> dictionaryCustomers = listCustomers.ToDictionary(x => x.ID);
        foreach (KeyValuePair<int, Customer> keyValuePairCustomers in dictionaryCustomers)
        {
            Console.WriteLine("Key = {0}", keyValuePairCustomers.Key);
            Customer c = keyValuePairCustomers.Value;
            Console.WriteLine("ID = {0}, Name = {1}, Salary = {2}", c.ID, c.Name, c.Salary);
        }
        Console.WriteLine("------------------------------------------------------");

        // To check if an item exists in the list use Contains() function
        // This method returns true if the items exists, else false
        if (listCustomers.Contains(customer2))
        {
            Console.WriteLine("Customer2 object exists in the list");
        }
        else
        {
            Console.WriteLine("Customer2 object does not exist in the list");
        }
        Console.WriteLine("------------------------------------------------------");

        // To check if an item exists in the list based on a condition, then use Exists() function
        // This method returns true if the items exists, else false
        if (listCustomers.Exists(x => x.Name.StartsWith("M")))
        {
            Console.WriteLine("List contains customer whose name starts with M");
        }
        else
        {
            Console.WriteLine("List does not contain a customer whose name starts with M");
        }
        Console.WriteLine("------------------------------------------------------");

        // Find() method searches for an element that matches the conditions defined by 
        // the specified lambda expression and returns the first matching item from the list
        Customer cust = listCustomers.Find(customer => customer.Salary > 5000);
        Console.WriteLine("ID = {0}, Name = {1}, Salary = {2}", cust.ID, cust.Name, cust.Salary);
        Console.WriteLine("------------------------------------------------------");

        // FindLast() method searches for an element that matches the conditions defined
        // by the specified lambda expression and returns the Last matching item from the list
        Customer lastMatch = listCustomers.FindLast(customer => customer.Salary > 5000);
        Console.WriteLine("ID = {0}, Name = {1}, Salary = {2}", lastMatch.ID, lastMatch.Name, lastMatch.Salary);
        Console.WriteLine("------------------------------------------------------");

        // FindAll() method returns all the items from the list that
        // match the conditions specified by the lambda expression
        List<Customer> filteredCustomers = listCustomers.FindAll(customer => customer.Salary > 5000);
        foreach (Customer cstmr in filteredCustomers)
        {
            Console.WriteLine("ID = {0}, Name = {1}, Salary = {2}", cstmr.ID, cstmr.Name, cstmr.Salary);
        }
        Console.WriteLine("------------------------------------------------------");

        // FindIndex() method returns the index of the first item, that matches the 
        // condition specified by the lambda expression. There are 2 other overloads 
        // of this method which allows us to specify the range of elements to 
        // search, with in the list.
        Console.WriteLine("Index of the first matching customer object whose salary is greater 5000 =" +
            listCustomers.FindIndex(customer => customer.Salary > 5000));
        Console.WriteLine("------------------------------------------------------");

        // FindLastIndex() method returns the index of the last item, 
        // that matches the condition specified by the lambda expression. 
        // There are 2 other overloads of this method which allows us to specify 
        // the range of elements to search, with in the list.
        Console.WriteLine("Index of the Last matching customer object whose salary is greater 5000 = " +
            listCustomers.FindLastIndex(customer => customer.Salary > 5000));
        Console.WriteLine("------------------------------------------------------");
    }
}

class TestColleciton
{
    static void Main(string[] args)
    {

        CollectionDemoMethod objCollMethod = new CollectionDemoMethod();
        objCollMethod.Show();
        Console.ReadLine();
    }
}

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