C# | Get an ICollection containing keys in OrderedDictionary

Last Updated : 11 Jul, 2025

OrderedDictionary.Keys property is used to get an ICollection object containing the keys in the OrderedDictionary collection. Syntax:

public System.Collections.ICollection Keys { get; }

Return Value: It returns an ICollection object containing the keys in the OrderedDictionary collection. Below given are some examples to understand the implementation in a better way: Example 1:

CSHARP

// C# code to get an ICollection
// containing the keys in OrderedDictionary
using System;
using System.Collections;
using System.Collections.Specialized;

class GFG {

    // Driver method
    public static void Main()
    {

        // Creating a orderedDictionary named myDict
        OrderedDictionary myDict = new OrderedDictionary();

        // Adding key and value in myDict
        myDict.Add("key1", "value1");
        myDict.Add("key2", "value2");
        myDict.Add("key3", "value3");
        myDict.Add("key4", "value4");
        myDict.Add("key5", "value5");

        // Getting an ICollection containing
        // the keys in OrderedDictionary
        ICollection keyCollection = myDict.Keys;

        // Creating a String array
        String[] myKeys = new String[myDict.Count];

        // Copying the OrderedDictionary elements to
        // a one-dimensional Array object at the
        // specified index.
        keyCollection.CopyTo(myKeys, 0);

        for (int i = 0; i < myDict.Count; i++) {
            Console.WriteLine(myKeys[i]);
        }
    }
}

Output:

key1
key2
key3
key4
key5

Example 2:

CSHARP

// C# code to get an ICollection
// containing the keys in OrderedDictionary
using System;
using System.Collections;
using System.Collections.Specialized;

class GFG {

    // Driver method
    public static void Main()
    {

        // Creating a orderedDictionary named myDict
        OrderedDictionary myDict = new OrderedDictionary();

        // Adding key and value in myDict
        myDict.Add("A", "Apple");
        myDict.Add("B", "Banana");
        myDict.Add("C", "Cat");
        myDict.Add("D", "Dog");

        // Getting an ICollection containing
        // the keys in OrderedDictionary
        ICollection keyCollection = myDict.Keys;

        // Creating a String array
        String[] myKeys = new String[myDict.Count];

        // Copying the OrderedDictionary elements to
        // a one-dimensional Array object at the
        // specified index.
        keyCollection.CopyTo(myKeys, 0);

        for (int i = 0; i < myDict.Count; i++) {
            Console.WriteLine(myKeys[i]);
        }
    }
}