C# | Check if Hashtable is read-only Last Updated : 01 Feb, 2019 Summarize Comments Improve Suggest changes Share Like Article Like Report Hashtable.IsReadOnly property is used to get a value indicating whether the Hashtable is read-only or not. Syntax: public virtual bool IsReadOnly { get; } Return Value: This property returns true if the Hashtable is read-only otherwise it returns false. The default is false. Below programs illustrate the above-discussed property: Example 1: CSharp // C# code to check if Hashtable // is read-only or not using System; using System.Collections; class GFG { // Driver code public static void Main() { // Creating a Hashtable Hashtable myTable = new Hashtable(); // Adding elements in Hashtable myTable.Add("G", "Geeks"); myTable.Add("C", "C#"); myTable.Add("D", "Data Structures"); myTable.Add("Q", "Quiz"); // Checking if Hashtable is read-only or not // this will return false Console.WriteLine(myTable.IsReadOnly); } } Output: False Example 2: CSharp // C# code to check if Hashtable // is read-only or not using System; using System.Collections; class GFG { // Driver code public static void Main() { // Creating a Hashtable Hashtable myTable = new Hashtable(); // Adding elements in Hashtable myTable.Add("1", "C"); myTable.Add("2", "C#"); myTable.Add("3", "C++"); myTable.Add("4", "HTML"); myTable.Add("5", "CSS"); // Checking if Hashtable is read-only or not // this will return false Console.WriteLine(myTable.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://docs.microsoft.com/en-us/dotnet/api/system.collections.hashtable.isreadonly?view=netframework-4.7.2 Comment More infoAdvertise with us Next Article C# | Check if Hashtable has a fixed size K Kirti_Mangal Follow Improve Article Tags : C# CSharp-Collections-Hashtable CSharp-Collections-Namespace Similar Reads C# | Check if Hashtable is synchronized (thread safe) Hashtable.IsSynchronized Property is used to get a value indicating whether access to the Hashtable is synchronized(thread-safe). Syntax: public virtual bool IsSynchronized { get; } Return Value: This property return true if access to the Hashtable is synchronized (thread-safe), otherwise it returns 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 a SortedList is read-only SortedList class is a collection of (key, value) pairs which are sorted according to keys. Those pairs can be accessible by key and as well as by index(zero-based indexing). This comes under System.Collections namespace. SortedList.IsReadOnly property is used to get a value which indicates that a So 2 min read C# | Check if the BitArray is read-only The BitArray class manages a compact array of bit values, which are represented as Booleans, where true indicates that the bit is on i.e, 1 and false indicates the bit is off i.e, 0. This class is contained in System.Collections namespace. BitArray.IsReadOnly property is used to get a value indicati 2 min read C# | Check if Hashtable has a fixed size Hashtable.IsFixedSize Property is used to get a value which indicates whether the Hashtable has a fixed size or not. Syntax: public virtual bool IsFixedSize { get; } Return Value: This property returns true if the Hashtable has a fixed size otherwise it returns false. The default is false. Below pro 2 min read C# | Check if the ArrayList is read-only ArrayList represents an ordered collection of an object that can be indexed individually. It is basically an alternative to an array. It also allows dynamic memory allocation, adding, searching and sorting items in the list. ArrayList.IsReadOnly property is used to check whether the ArrayList is rea 2 min read Like