List

Data Structure 

1. IEnumerable
2. IQueryable
3. Dictionary and IDictionary
4. ICollection
5. HashTable
6. IList or List

7. ArrayList 

http://www.dotnet-tricks.com/Tutorial/csharp/bDRH230314-Understanding-Collections-and-Collections-Interfaces.html

http://www.dotnet-tricks.com/Tutorial/linq/I8SY160612-IEnumerable-VS-IQueryable.html

*******************IEnumerable***************************

IEnumerable exists in System.Collections Namespace.

MyDataContext dc = new MyDataContext ();

IEnumerable<Employee> list = dc.Employees.Where(p => p.Name.StartsWith("S"));

list = list.Take<Employee>(10);

SELECT [t0].[EmpID], [t0].[EmpName], [t0].[Salary] FROM [Employee] AS [t0]WHERE [t0].[EmpName] LIKE @p0

*******************IQueryable ***************************

IQueryable exists in System.Linq Namespace.

MyDataContext dc = new MyDataContext ();
IQueryable<Employee> list = dc.Employees.Where(p => p.Name.StartsWith("S"));
list = list.Take<Employee>(10); 

SELECT TOP 10 [t0].[EmpID], [t0].[EmpName], [t0].[Salary] FROM [Employee] AS [t0] WHERE [t0].[EmpName] LIKE @p0

Notice that in this query "top 10" is exist since IQueryable executes query in SQL server with all filters.

************** HashTable*************************

 Hashtable weeks = new Hashtable();
            weeks.Add("1", "SunDay");
            weeks.Add("2", "MonDay");
            weeks.Add("3", "TueDay");
            weeks.Add("4", "WedDay");
            weeks.Add("5", "ThuDay");
            weeks.Add("6", "FriDay");
            weeks.Add("7", "SatDay");
            //Display a single Item 
            MessageBox.Show(weeks["5"].ToString ());
            //Search an Item 
            if (weeks.ContainsValue("TueDay"))
            {
                MessageBox.Show("Find");
            }
            else
            {
                MessageBox.Show("Not find");
            }

            //remove an Item 
            weeks.Remove("3");
            //Display all key value pairs
            foreach (DictionaryEntry day in weeks )
            {
                MessageBox.Show (day.Key + "   -   " + day.Value );
            }

************* ArrayList *****************

 int i = 0;
            ArrayList ItemList = new ArrayList();
            ItemList.Add("Item4");
            ItemList.Add("Item5");
            ItemList.Add("Item2");
            ItemList.Add("Item1");
            ItemList.Add("Item3");
            MessageBox.Show ("Shows Added Items");
            for (i = 0; i < = ItemList.Count - 1; i++)
            {
                MessageBox.Show(ItemList[i].ToString());
            }
            //insert an item 
            ItemList.Insert(3, "Item6");
            //sort itemms in an arraylist 
            ItemList.Sort();
            //remove an item 
            ItemList.Remove("Item1");
            //remove item from a specified index 
            ItemList.RemoveAt(3);
            MessageBox.Show("Shows final Items the ArrayList");
            for (i = 0; i < = ItemList.Count - 1; i++)
            {
                MessageBox.Show(ItemList[i].ToString());
            }

***************IList or List****************

http://www.dotnet-tricks.com/Tutorial/linq/VXTY160612-IEnumerable-VS-IList.html

 List < string > colors = new List < string > ();
            //add items in a List collection
            colors.Add("Red");
            colors.Add("Blue");
            colors.Add("Green");
            //insert an item in the list
            colors.Insert(1, "violet");
            //retrieve items using foreach loop
            foreach (string color in colors)
            {
                MessageBox.Show(color);
            }
            //remove an item from list
            colors.Remove("violet");
            //retrieve items using for loop
            for (int i = 0; i < colors.Count; i++)
            {
                MessageBox.Show(colors[i]);
            }
            if (colors.Contains("Blue"))
            {
                MessageBox.Show("Blue color exist in the list");
            }
            else
            {
                MessageBox.Show("Not exist");
            }

            //copy array to list
            string[] strArr = new string[3];
            strArr[0] = "Red";
            strArr[1] = "Blue";
            strArr[2] = "Green";
            List < string > arrlist = new List < string > (strArr);
            foreach (string str in strArr)
            {
                MessageBox.Show(str);
            }
            //call clear method
            arrlist.Clear ();
            MessageBox.Show(arrlist.Count.ToString ());
        }

******* Dictionary and IDictionary**********

Dictionary is a generic type, Hashtable is not. That means you get type safety with Dictionary, because you can't insert any random object into it, and you don't have to cast the values you take out. Since both Dictionary and Hashtable are internally hashtables

Dictionary < string, int > dict = new Dictionary < string, int > ();
dict.Add("one", 1);
dict.Add("two", 2);
dict.Add("three", 3);
dict.Add("four", 4);

foreach (KeyValuePair < string, int >  pair in dict)
{
 MessageBox.Show(pair.Key.ToString() + "  -  " + pair.Value.ToString());
}

***************************************

Operation 

Algorithm = > Operation

http://auk-port.blogspot.com/2012/08/difference-among-ienumerable-iqueryable_5620.html

http://people.cs.aau.dk/~normark/oop-csharp/html/notes/collections_themes-list-sect.html

http://www.dotnet-tricks.com/Tutorial/linq/I8SY160612-IEnumerable-VS-IQueryable.html