C# | Check if OrderedDictionary collection is read-only

OrderedDictionary.IsReadOnly property is used to get a value that indicates whether the OrderedDictionary collection is read-only or not.

Syntax :

public bool IsReadOnly { get; }

Return Value: This property returns True if the OrderedDictionary collection is read-only, otherwise, False. The default is False.

Below given are some examples to understand the implementation in a better way:

Example 1:

// C# code to check if OrderedDictionary
// collection is read-only
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");

        // Checking if OrderedDictionary
        // collection is read-only
        Console.WriteLine(myDict.IsReadOnly);
    }
}

Output:

False

Example 2:

// C# code to check if OrderedDictionary
// collection is read-only
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");

        // Checking if OrderedDictionary
        // collection is read-only
        // if not, insert a new key in beginning
        // of myDict
        if (!myDict.IsReadOnly)
            myDict.Insert(0, "E", "Elephant");

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

Output:

E -- Elephant
A -- Apple
B -- Banana
C -- Cat
D -- Dog

Note:

• A collection that is read-only does not allow the addition, removal, or modification of elements after the collection is created.
• A collection that is read-only is simply a collection with a wrapper that prevents modification of the collection. Therefore, if changes are made to the underlying collection, the read-only collection reflects those changes.

Reference:

• https://docs.microsoft.com/en-us/dotnet/api/system.collections.specialized.ordereddictionary.isreadonly?view=netframework-4.7.2