Get an enumerator that iterates through the SortedList in C#

The SortedList class in C# provides the GetEnumerator() method to retrieve an enumerator that iterates through key-value pairs. This method returns an IDictionaryEnumerator object that allows sequential access to each element in the sorted collection.

Syntax

Following is the syntax for getting an enumerator from a SortedList −

IDictionaryEnumerator enumerator = sortedList.GetEnumerator();

Following is the syntax for iterating using the enumerator −

while (enumerator.MoveNext()) {
   Console.WriteLine("Key = " + enumerator.Key + ", Value = " + enumerator.Value);
}

Return Value

The GetEnumerator() method returns an IDictionaryEnumerator object for the SortedList. This enumerator provides three important properties −

• Key − Gets the key of the current dictionary entry

• Value − Gets the value of the current dictionary entry

• Entry − Gets both the key and value as a DictionaryEntry

Using GetEnumerator() with Alphabetic Keys

Example

using System;
using System.Collections;

public class Demo {
   public static void Main(String[] args) {
      SortedList sortedList = new SortedList();
      sortedList.Add("A", "1");
      sortedList.Add("B", "2");
      sortedList.Add("C", "3");
      sortedList.Add("D", "4");
      sortedList.Add("E", "5");
      sortedList.Add("F", "6");
      sortedList.Add("G", "7");
      sortedList.Add("H", "8");
      sortedList.Add("I", "9");
      sortedList.Add("J", "10");
      
      Console.WriteLine("SortedList elements...");
      foreach(DictionaryEntry d in sortedList) {
         Console.WriteLine("Key = " + d.Key + ", Value = " + d.Value);
      }
      Console.WriteLine("Count of SortedList key-value pairs = " + sortedList.Count);
      Console.WriteLine("\nEnumerator to iterate through the SortedList...");
      
      IDictionaryEnumerator demoEnum = sortedList.GetEnumerator();
      while (demoEnum.MoveNext())
         Console.WriteLine("Key = " + demoEnum.Key + ", Value = " + demoEnum.Value);
   }
}

The output of the above code is −

SortedList elements...
Key = A, Value = 1
Key = B, Value = 2
Key = C, Value = 3
Key = D, Value = 4
Key = E, Value = 5
Key = F, Value = 6
Key = G, Value = 7
Key = H, Value = 8
Key = I, Value = 9
Key = J, Value = 10
Count of SortedList key-value pairs = 10

Enumerator to iterate through the SortedList...
Key = A, Value = 1
Key = B, Value = 2
Key = C, Value = 3
Key = D, Value = 4
Key = E, Value = 5
Key = F, Value = 6
Key = G, Value = 7
Key = H, Value = 8
Key = I, Value = 9
Key = J, Value = 10

Using GetEnumerator() with Word Keys

Example

using System;
using System.Collections;

public class Demo {
   public static void Main(String[] args) {
      SortedList sortedList = new SortedList();
      sortedList.Add("One", "1");
      sortedList.Add("Two", "2");
      sortedList.Add("Three", "3");
      sortedList.Add("Four", "4");
      sortedList.Add("Five", "5");
      sortedList.Add("Six", "6");
      sortedList.Add("Seven", "7");
      sortedList.Add("Eight", "8");
      sortedList.Add("Nine", "9");
      sortedList.Add("Ten", "10");
      
      Console.WriteLine("Enumerator to iterate through the SortedList...");
      IDictionaryEnumerator demoEnum = sortedList.GetEnumerator();
      while (demoEnum.MoveNext())
         Console.WriteLine("Key = " + demoEnum.Key + ", Value = " + demoEnum.Value);
   }
}

The output of the above code is −

Enumerator to iterate through the SortedList...
Key = Eight, Value = 8
Key = Five, Value = 5
Key = Four, Value = 4
Key = Nine, Value = 9
Key = One, Value = 1
Key = Seven, Value = 7
Key = Six, Value = 6
Key = Ten, Value = 10
Key = Three, Value = 3
Key = Two, Value = 2

Comparison: foreach vs GetEnumerator()

Conclusion

The GetEnumerator() method provides manual control over SortedList iteration by returning an IDictionaryEnumerator. This approach is useful when you need fine-grained control over the enumeration process, while foreach offers a simpler alternative for standard iterations.