Sorted list in C# is a collection of Key-Value pairs, Values are accessed via Key or by Index. It's generic so we can choose any datatype for Key. Key must be unique while we can have duplicate values. Key are sorted automatically, due to this it's a bit slower as compared to HashTable or Dictionary.
Removing or adding a item in sorted list will change index of items as it will sort keys.
Below are some important methods exposed by SortedList.
public TKey GetKeyAtIndex(int index);
public TValue GetValueAtIndex(int index);
public int IndexOfKey(TKey key);
public int IndexOfValue(TValue value);
public void SetValueAtIndex(int index, TValue value);
Example: Copy and paste below code in VSCode/VisualStudio
public static void WorkingWithSortedList()
{
//Soreted list is a collection of sorted key value pair.
// data can be accessed via key or index.
var list = new SortedList<int, string>();
list.Add(1, "One");
list.Add(2, "Two");
list.Add(3, "Three");
// list.Add(2, "Two"); //Duplicates are not allowed.
list.Add(5, "Five");
list.Add(6, "Six");
list.Add(4, "Four");//Adding at last but it would get added at index (3);
list.Add(7, "One"); // Duplicate values are allowed!
Console.WriteLine(list.Count);
Console.WriteLine("Accessiing sorted list elements");
//Below loop will print item which is Key-value pair object
foreach (var item in list)
{ Console.WriteLine("Sorted list is a collection of KeyValue :" + item); }
foreach (var item in list)
{ Console.WriteLine($"item Key={item.Key}, Value={item.Value}"); }
for(int i = 0; i < list.Count; i++) {
Console.WriteLine($"Item at index {i}={list.GetKeyAtIndex(i)} ,{list.GetValueAtIndex(i)}");
}
//Chning item for key=2
list[2] = "Two Changed";
foreach (var item in list) {
Console.WriteLine(item);
Console.WriteLine($"item Key={item.Key}, Value={item.Value}");
}
Console.WriteLine( "Getting index of last added item i.e.4");
Console.WriteLine( list.IndexOfKey(4));
Console.WriteLine("Getting index of value Four");
Console.WriteLine(list.IndexOfValue("Four"));
Console.WriteLine("Index of above key-value would get changed as removing itewm from index 2");
list.Remove(2); //removed item by key;
Console.WriteLine("Getting index of last added item i.e.4");
Console.WriteLine(list.IndexOfKey(4));
Console.WriteLine("Getting index of value Four");
Console.WriteLine(list.IndexOfValue("Four"));
Console.WriteLine( "***********Prining Keys ****************");
foreach(var key in list.Keys) { Console.WriteLine(key); }
Console.WriteLine("***********Prining Values ****************");
foreach (var val in list.Values) { Console.WriteLine(val); }
Console.WriteLine(" WHat if trying to access key which is not present");
// Console.WriteLine(list[8]); // Thow exception as no item at index 8
}
