C# | Remove all elements from OrderedDictionary

Last Updated : 11 Jul, 2025
OrderedDictionary.Clear method is used to remove all elements from the OrderedDictionary collection. Syntax: 
public void Clear ();
Exception: If the OrderedDictionary collection is read-only then it will throw NotSupportedException. Below given are some examples to understand the implementation in a better way: Example 1: CSHARP 
// C# code to remove all elements
// from 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");

        // Displaying the number of element initially
        Console.WriteLine("Number of elements are : " + myDict.Count);

        // Displaying the elements in myDict
        foreach(DictionaryEntry de in myDict)
            Console.WriteLine(de.Key + " -- " + de.Value);

        // Removing all elements from OrderedDictionary
        myDict.Clear();

        // Displaying the number of element initially
        Console.WriteLine("Number of elements are : " + myDict.Count);

        // Displaying the elements in myDict
        foreach(DictionaryEntry de in myDict)
            Console.WriteLine(de.Key + " -- " + de.Value);
    }
}
Output: 
Number of elements are : 5
key1 -- value1
key2 -- value2
key3 -- value3
key4 -- value4
key5 -- value5
Number of elements are : 0
Example 2: CSHARP 
// C# code to remove all elements
// from 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");

        // Displaying the number of element initially
        Console.WriteLine("Number of elements are : " + myDict.Count);

        // Displaying the elements in myDict
        foreach(DictionaryEntry de in myDict)
            Console.WriteLine(de.Key + " -- " + de.Value);

        // Removing all elements from OrderedDictionary
        myDict.Clear();

        // Displaying the number of element initially
        Console.WriteLine("Number of elements are : " + myDict.Count);

        // Displaying the elements in myDict
        foreach(DictionaryEntry de in myDict)
            Console.WriteLine(de.Key + " -- " + de.Value);
    }
}
Output: 
Number of elements are : 4
A -- Apple
B -- Banana
C -- Cat
D -- Dog
Number of elements are : 0
Note:
  • After calling the Clear method, the Count property is set to zero.
  • References to other objects from elements of the collection are also released.
  • The capacity of dictionary is not changed as a result of calling this method.
Reference:
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