C# | Check if ListDictionary is read-only Last Updated : 11 Jul, 2025 Summarize Comments Improve Suggest changes Share Like Article Like Report ListDictionary.IsReadOnly property is used to get a value indicating whether the ListDictionary is read-only or not. Syntax: public bool IsReadOnly { get; } Return Value : This property always returns false. Example: CSHARP // C# code to check if ListDictionary is read-only using System; using System.Collections; using System.Collections.Specialized; class GFG { // Driver code public static void Main() { // Creating a ListDictionary named myDict ListDictionary myDict = new ListDictionary(); myDict.Add("Australia", "Canberra"); myDict.Add("Belgium", "Brussels"); myDict.Add("Netherlands", "Amsterdam"); myDict.Add("China", "Beijing"); myDict.Add("Russia", "Moscow"); myDict.Add("India", "New Delhi"); // Checking if ListDictionary is read-only Console.WriteLine(myDict.IsReadOnly); } } Output: False 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 modifying the collection. Therefore, if changes are made to the underlying collection, the read-only collection reflects those changes. Retrieving the value of this property is an O(1) operation. Reference: https://learn.microsoft.com/en-us/dotnet/api/system.collections.specialized.listdictionary.isreadonly?view=netframework-4.7.2 Comment More infoAdvertise with us Next Article C# | Check if StringDictionary is synchronized (thread safe) S Sahil_Bansall Follow Improve Article Tags : C# CSharp-Specialized-Namespace CSharp-Specialized-ListDictionary Similar Reads C# | Check if ListDictionary is synchronized (thread safe) ListDictionary.IsSynchronized property is used to get a value indicating whether the ListDictionary is synchronized (thread safe) or not. Syntax: public bool IsSynchronized { get; } Return Value: This property always returns false. Below are the programs to illustrate the use of ListDictionary.IsSyn 1 min read C# | Check if ListDictionary is synchronized (thread safe) ListDictionary.IsSynchronized property is used to get a value indicating whether the ListDictionary is synchronized (thread safe) or not. Syntax: public bool IsSynchronized { get; } Return Value: This property always returns false. Below are the programs to illustrate the use of ListDictionary.IsSyn 1 min read C# | Check if HybridDictionary is read only HybridDictionary.IsReadOnly property is used to get a value that indicates whether the HybridDictionary is read-only or not. Syntax: public bool IsReadOnly { get; } Return Value: This property always returns false. Below programs illustrate the use of HybridDictionary.IsReadOnly property: Example 1: 2 min read C# | Check if HybridDictionary is read only HybridDictionary.IsReadOnly property is used to get a value that indicates whether the HybridDictionary is read-only or not. Syntax: public bool IsReadOnly { get; } Return Value: This property always returns false. Below programs illustrate the use of HybridDictionary.IsReadOnly property: Example 1: 2 min read C# | Check if StringDictionary is synchronized (thread safe) StringDictionary.IsSynchronized property is used to get a value indicating whether access to the StringDictionary is synchronized (thread-safe). Syntax: public virtual bool IsSynchronized { get; } Return Value: This method returns True if access to the StringDictionary is synchronized (thread safe), 1 min read C# | Check if StringDictionary is synchronized (thread safe) StringDictionary.IsSynchronized property is used to get a value indicating whether access to the StringDictionary is synchronized (thread-safe). Syntax: public virtual bool IsSynchronized { get; } Return Value: This method returns True if access to the StringDictionary is synchronized (thread safe), 1 min read Like