Set all bits in the BitArray to the specified value in C#

The BitArray.SetAll() method in C# is used to set all bits in the BitArray to a specified boolean value. This method provides an efficient way to initialize or reset all elements in a BitArray with a single operation, rather than setting each bit individually.

Syntax

Following is the syntax for the SetAll() method −

public void SetAll(bool value)

Parameters

value: A boolean value (true or false) to assign to all bits in the BitArray.

Using SetAll() to Set All Bits to True

The following example demonstrates setting all bits in a BitArray to true −

using System;
using System.Collections;

public class Demo {
   public static void Main() {
      BitArray arr = new BitArray(5);
      arr[0] = false;
      arr[1] = false;
      arr[2] = false;
      arr[3] = false;
      Console.WriteLine("BitArray...");
      foreach(Object ob in arr) {
         Console.WriteLine(ob);
      }
      arr.SetAll(true);
      Console.WriteLine("\nUpdated BitArray...");
      foreach(Object ob in arr) {
         Console.WriteLine(ob);
      }
   }
}

The output of the above code is −

BitArray...
False
False
False
False
False

Updated BitArray...
True
True
True
True
True

Using SetAll() to Set All Bits to False

The following example demonstrates setting all bits in a BitArray to false −

using System;
using System.Collections;

public class Demo {
   public static void Main() {
      BitArray arr = new BitArray(5);
      arr[0] = true;
      arr[1] = false;
      arr[2] = true;
      arr[3] = false;
      Console.WriteLine("BitArray...");
      foreach(Object ob in arr) {
         Console.WriteLine(ob);
      }
      arr.SetAll(false);
      Console.WriteLine("\nUpdated BitArray...");
      foreach(Object ob in arr) {
         Console.WriteLine(ob);
      }
   }
}

The output of the above code is −

BitArray...
True
False
True
False
False

Updated BitArray...
False
False
False
False
False

Practical Example with Boolean Operations

Here's a more practical example showing how SetAll() can be used for bulk operations −

using System;
using System.Collections;

public class Demo {
   public static void Main() {
      BitArray flags = new BitArray(8);
      
      Console.WriteLine("Initial BitArray (all false by default):");
      PrintBitArray(flags);
      
      // Enable all flags
      flags.SetAll(true);
      Console.WriteLine("\nAfter SetAll(true):");
      PrintBitArray(flags);
      
      // Reset all flags
      flags.SetAll(false);
      Console.WriteLine("\nAfter SetAll(false):");
      PrintBitArray(flags);
   }
   
   static void PrintBitArray(BitArray arr) {
      for(int i = 0; i 

The output of the above code is −

Initial BitArray (all false by default):
00000000

After SetAll(true):
11111111

After SetAll(false):
00000000


Conclusion

The SetAll() method provides an efficient way to set all bits in a BitArray to the same value with a single method call. It's particularly useful for initialization, resetting flags, or performing bulk operations on BitArray collections.