C# | Number of elements contained in the BitArray

Last Updated : 11 Jul, 2025

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.Count property is used to get the number of elements contained in the BitArray. Properties:

The BitArray class is a collection class in which the capacity is always the same as the count.
Elements are added to a BitArray by increasing the Length property.
Elements are deleted by decreasing the Length property.
Elements in this collection can be accessed using an integer index. Indexes in this collection are zero-based.

Syntax:

 public int Count { get; }

Below programs illustrate the use of BitArray.Count Property: Example 1:

CSHARP

// C# code to get the number of  // elements contained in the BitArray using System; using System.Collections; class GFG {  // Driver code  public static void Main()  {  // Creating a BitArray  BitArray myBitArr = new BitArray(new byte[] { 0, 1, 0, 1 });  // To get the number of elements  // contained in the BitArray  Console.WriteLine(myBitArr.Count);  } }

Output:

Example 2:

CSHARP

// C# code to get the number of // elements contained in the BitArray using System; using System.Collections; class GFG {  // Driver code  public static void Main()  {  // Creating a BitArray  BitArray myBitArr = new BitArray(new byte[] { 0 });  // To get the number of elements  // contained in the BitArray  Console.WriteLine(myBitArr.Count);  } }

Output:

Note:

Length and Count return the same value. Length can be set to a specific value, but Count is read-only.
Retrieving the value of this property is an O(1) operation.

Reference: