Introduction
The SortedList<> class represents a collection of key/value pairs that are sorted by key. The hierarchy of SortedList is System.Collections.Generic.SortedList<TKey, TValue>, where Tkey is the type of keys in the collection and Tvalue is the type of values in the collection. In this article I explain how to create the SortedList and the various mathods and properties of SortedList.
Creation of SortedList
We can create the SortedList by the following line of code:
SortedList<int, string> sortedlist = new SortedList<int, string>();
Add elements in SortedList
We can add the elements by using the add() method. For example:
namespace SortedList
{
class Program
{
static void Main(string[] args)
{
//creation of sortedlist
SortedList<int, string> sortedlist = new SortedList<int, string>();
//add the elements in sortedlist
sortedlist.Add(1, "Sunday");
sortedlist.Add(2, "Monday");
sortedlist.Add(3, "Tuesday");
sortedlist.Add(4, "Wednesday");
sortedlist.Add(5, "Thusday");
sortedlist.Add(6, "Friday");
sortedlist.Add(7, "Saturday");
//display the elements of the sortedlist
Console.WriteLine("The elements in the SortedList are:");
foreach (KeyValuePair<int, string> pair in sortedlist)
{
Console.WriteLine("{0} => {1}", pair.Key, pair.Value);
}
}
}
}
Output
![sortedlist1.jpg]()
Properties
Capacity : Gets or sets the number of elements that the SortedList<TKey, TValue> can contain. The bydefault value of capacity is 4, which allows for 4 elements to be added to the list, and if we enter the 5th element then the capacity increases by 4, which means if there are 5 elements in the list then the capacity will be 8. In the following example we add an element with the number 7 so that the capacity will be 8; if we add 9 elements then the capacity will be 16 (double the previous one).
namespace SortedList
{
class Program
{
static void Main(string[] args)
{
//creation of sortedlist
SortedList<int, string> sortedlist = new SortedList<int, string>();
//add the elements in sortedlist
sortedlist.Add(1, "Sunday");
sortedlist.Add(2, "Monday");
sortedlist.Add(3, "Tuesday");
sortedlist.Add(4, "Wednesday");
sortedlist.Add(5, "Thusday");
sortedlist.Add(6, "Friday");
sortedlist.Add(7, "Saturday");
//display the elements of the sortedlist
Console.WriteLine("The elements in the SortedList are:");
foreach (KeyValuePair<int, string> pair in sortedlist)
{
Console.WriteLine("{0} => {1}", pair.Key, pair.Value);
}
//Find the capacity
Console.WriteLine("The capacity is:" + sortedlist.Capacity);
sortedlist.Add(8, "januray");
sortedlist.Add(9, "april");
Console.WriteLine("After adding two more element the capacity is:" + sortedlist.Capacity);
}
}
}
Output
![sortedlist2.jpg]()
Count : The Count property counts the number of elements in the SortedList or we can say that Count gets the number of key/value pairs contained in the SortedList<TKey, TValue>. For example:
namespace SortedList
{
class Program
{
static void Main(string[] args)
{
//creation of sortedlist
SortedList<int, string> sortedlist = new SortedList<int, string>();
//add the elements in sortedlist
sortedlist.Add(1, "Sunday");
sortedlist.Add(2, "Monday");
sortedlist.Add(3, "Tuesday");
sortedlist.Add(4, "Wednesday");
sortedlist.Add(5, "Thusday");
sortedlist.Add(6, "Friday");
sortedlist.Add(7, "Saturday");
//display the elements of the sortedlist
Console.WriteLine("The elements in the SortedList are:");
foreach (KeyValuePair<int, string> pair in sortedlist)
{
Console.WriteLine("{0} => {1}", pair.Key, pair.Value);
}
Console.WriteLine("The total number of elements in the sortedlist are:" + sortedlist.Count);
sortedlist.Add(8, "januray");
sortedlist.Add(9, "april");
Console.WriteLine("After adding two more element the number of element in sortedlist are:" + sortedlist.Count);
}
}
}
Output
![sortedlist3.jpg]()
Difference between Capacity and Count
![difference.jpg]()
Keys : It gets a collection containing the keys in the SortedList<TKey, TValue>; for this we use IList, for example:
namespace SortedList
{
class Program
{
static void Main(string[] args)
{
//creation of sortedlist
SortedList<int, string> sortedlist = new SortedList<int, string>();
//add the elements in sortedlist
sortedlist.Add(1, "Sunday");
sortedlist.Add(2, "Monday");
sortedlist.Add(3, "Tuesday");
sortedlist.Add(4, "Wednesday");
sortedlist.Add(5, "Thusday");
sortedlist.Add(6, "Friday");
sortedlist.Add(7, "Saturday");
//display the elements of the sortedlist
Console.WriteLine("The elements in the SortedList are:");
foreach (KeyValuePair<int, string> pair in sortedlist)
{
Console.WriteLine("{0} => {1}", pair.Key, pair.Value);
}
IList<int> ilistKeys = sortedlist.Keys;
Console.WriteLine();
Console.WriteLine("The keys are:");
Console.Write("{");
foreach (int i in ilistKeys)
{
Console.Write(i + ",");
}
Console.WriteLine("}");
}
}
}
Output
![sortedlist4.jpg]()
Values : Gets a collection containing the values in the SortedList<TKey, TValue>. For example:
namespace SortedList
{
class Program
{
static void Main(string[] args)
{
//creation of sortedlist
SortedList<int, string> sortedlist = new SortedList<int, string>();
//add the elements in sortedlist
sortedlist.Add(1, "Sunday");
sortedlist.Add(2, "Monday");
sortedlist.Add(3, "Tuesday");
sortedlist.Add(4, "Wednesday");
sortedlist.Add(5, "Thusday");
sortedlist.Add(6, "Friday");
sortedlist.Add(7, "Saturday");
//display the elements of the sortedlist
Console.WriteLine("The elements in the SortedList are:");
foreach (KeyValuePair<int, string> pair in sortedlist)
{
Console.WriteLine("{0} => {1}", pair.Key, pair.Value);
}
IList<string> ilistvalues = sortedlist.Values;
Console.WriteLine();
Console.WriteLine("The Values are:");
Console.WriteLine();
Console.Write("{");
foreach (string i in ilistvalues)
{
Console.Write(i + ",");
}
Console.WriteLine("}");
}
}
}
Output
![sortedlist5.jpg]()
Methods
ContainsKey() : Determines whether the SortedList<TKey, TValue> contains a specific key. For example:
namespace SortedList
{
class Program
{
static void Main(string[] args)
{
//creation of sortedlist
SortedList<int, string> sortedlist = new SortedList<int, string>();
//add the elements in sortedlist
sortedlist.Add(1, "Sunday");
sortedlist.Add(2, "Monday");
sortedlist.Add(3, "Tuesday");
sortedlist.Add(4, "Wednesday");
sortedlist.Add(5, "Thusday");
sortedlist.Add(6, "Friday");
sortedlist.Add(7, "Saturday");
//display the elements of the sortedlist
Console.WriteLine("The elements in the SortedList are:");
foreach (KeyValuePair<int, string> pair in sortedlist)
{
Console.WriteLine("{0} => {1}", pair.Key, pair.Value);
}
//apply contain key method
Console.WriteLine("The key 1 contain in the SortedList:" + sortedlist.ContainsKey(1));
Console.WriteLine("The key 5 contain in the SortedList:" + sortedlist.ContainsKey(5));
Console.WriteLine("The key 10 contain in the SortedList:" + sortedlist.ContainsKey(10));
Console.WriteLine("The key 50 contain in the SortedList:" + sortedlist.ContainsKey(50));
}
}
}
Output
![containkey.jpg]()
ContainsValue() : Determines whether the SortedList<TKey, TValue> contains a specific value. For example:
namespace SortedList
{
class Program
{
static void Main(string[] args)
{
//creation of sortedlist
SortedList<int, string> sortedlist = new SortedList<int, string>();
//add the elements in sortedlist
sortedlist.Add(1, "Sunday");
sortedlist.Add(2, "Monday");
sortedlist.Add(3, "Tuesday");
sortedlist.Add(4, "Wednesday");
sortedlist.Add(5, "Thusday");
sortedlist.Add(6, "Friday");
sortedlist.Add(7, "Saturday");
//display the elements of the sortedlist
Console.WriteLine("The elements in the SortedList are:");
foreach (KeyValuePair<int, string> pair in sortedlist)
{
Console.WriteLine("{0} => {1}", pair.Key, pair.Value);
}
//apply contain value method
Console.WriteLine("The value Sunday contain in the SortedList:" + sortedlist.ContainsValue("Sunday"));
Console.WriteLine("The value Friday contain in the SortedList:" + sortedlist.ContainsValue("Friday"));
Console.WriteLine("The value May contain in the SortedList:" + sortedlist.ContainsValue("May"));
Console.WriteLine("The value Wednesday contain in the SortedList:" + sortedlist.ContainsValue("Wednesday"));
}
}
}
Output
![containvalue.jpg]()
Clear() : Removes all elements from the SortedList<TKey, TValue>. For example:
namespace SortedList
{
class Program
{
static void Main(string[] args)
{
//creation of sortedlist
SortedList<int, string> sortedlist = new SortedList<int, string>();
//add the elements in sortedlist
sortedlist.Add(1, "Sunday");
sortedlist.Add(2, "Monday");
sortedlist.Add(3, "Tuesday");
sortedlist.Add(4, "Wednesday");
sortedlist.Add(5, "Thusday");
sortedlist.Add(6, "Friday");
sortedlist.Add(7, "Saturday");
Console.WriteLine("The number of elements in the sortedlist are:" + sortedlist.Count);
//apply clear method
sortedlist.Clear();
Console.WriteLine("After clear method the elements in the sortedlist are:" + sortedlist.Count);
}
}
}
Output
![clear.jpg]()
IndexOfKey() : Searches the specified key and returns the index value of that key.
IndexOfValue() : Searches the specified value and returns the index value of that value.
The following example shows the use of both IndexOfKey and IndexOfValue methods
namespace SortedList
{
class Program
{
static void Main(string[] args)
{
//creation of sortedlist
SortedList<int, string> sortedlist = new SortedList<int, string>();
//add the elements in sortedlist
sortedlist.Add(1, "Sunday");
sortedlist.Add(2, "Monday");
sortedlist.Add(3, "Tuesday");
sortedlist.Add(4, "Wednesday");
sortedlist.Add(5, "Thusday");
sortedlist.Add(6, "Friday");
sortedlist.Add(7, "Saturday");
//IndexOfKey method
Console.WriteLine("***************INDEXOFKEY***************");
Console.WriteLine();
Console.WriteLine("The index value of the key 4 is:" + sortedlist.IndexOfKey(4));
Console.WriteLine("The index value of the key 1 is:" + sortedlist.IndexOfKey(1));
Console.WriteLine("The index value of the key 7 is:" + sortedlist.IndexOfKey(7));
Console.WriteLine("The index value of the key 2 is:" + sortedlist.IndexOfKey(2));
//IndexofValue method
Console.WriteLine();
Console.WriteLine("***************INDEXOFVALUE***************");
Console.WriteLine();
Console.WriteLine("The index value of the value Sunday is:" + sortedlist.IndexOfValue("Sunday"));
Console.WriteLine("The index value of the value Wednesday is:" + sortedlist.IndexOfValue("Wednesday"));
Console.WriteLine("The index value of the value Monday is:" + sortedlist.IndexOfValue("Monday"));
Console.WriteLine("The index value of the value Friday is:" + sortedlist.IndexOfValue("Friday"));
}
}
}
Output
![indexofkey.jpg]()
Remove() : Removes the element with the specified key from the SortedList<TKey, TValue>. For example:
namespace SortedList
{
class Program
{
static void Main(string[] args)
{
//creation of sortedlist
SortedList<int, string> sortedlist = new SortedList<int, string>();
//add the elements in sortedlist
sortedlist.Add(1, "Sunday");
sortedlist.Add(2, "Monday");
sortedlist.Add(3, "Tuesday");
sortedlist.Add(4, "Wednesday");
sortedlist.Add(5, "Thusday");
sortedlist.Add(6, "Friday");
sortedlist.Add(7, "Saturday");
//display the elements of the sortedlist
Console.WriteLine("The elements in the SortedList are:");
foreach (KeyValuePair<int, string> pair in sortedlist)
{
Console.WriteLine("{0} => {1}", pair.Key, pair.Value);
}
//remove the elements from the sortedlist
sortedlist.Remove(3);
sortedlist.Remove(7);
sortedlist.Remove(1);
Console.WriteLine("After remove some elements the sortedlist is as:");
foreach (KeyValuePair<int, string> pair1 in sortedlist)
{
Console.WriteLine("{0} => {1}", pair1.Key, pair1.Value);
}
}
}
}
Output
![remove.jpg]()
Summary
In this article I explained how to create the SortedList in C# and the various methods and properties of SortedList.