Java BitSet size() Method

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Description

The Java BitSet size() method returns the number of bits of space actually in use by this BitSet to represent bit values. The maximum element in the set is the size - 1st element.

Declaration

Following is the declaration for java.util.BitSet.size() method

public int size()

Parameters

NA

Return Value

This method returns the number of bits currently in this bit set.

Exception

NA

Example 1

The following example shows the usage of Java BitSet size() method. We're creating two BitSets. We're setting true values at given indexes to the BitSet objects using set() method calls per index and using size() method we're printing the actual size of bitsets.

package com.tutorialspoint;
import java.util.BitSet;
public class BitSetDemo {
   public static void main(String[] args) {

      // create 2 bitsets
      BitSet bitset1 = new BitSet();
      BitSet bitset2 = new BitSet();

      // assign values to bitset1
      bitset1.set(0, 6, true);

      // assign values to bitset2
      bitset2.set(2);
      bitset2.set(4);
      bitset2.set(6);
      bitset2.set(8);
      bitset2.set(10);

      // print the sets
      System.out.println("Bitset1:" + bitset1);
      System.out.println("Bitset2:" + bitset2);
	  
      // print the size of the sets
      System.out.println(bitset1.size());
      System.out.println(bitset2.size());
   }
}

Let us compile and run the above program, this will produce the following result −

Bitset1:{0, 1, 2, 3, 4, 5}
Bitset2:{2, 4, 6, 8, 10}
64
64

Example 2

The following example shows the usage of Java BitSet size() method. We're creating two BitSets using byte[] and using size() method we're printing the size of the bitsets.

package com.tutorialspoint;
import java.util.BitSet;
public class BitSetDemo {
   public static void main(String[] args) {

      // create 2 bitsets
      BitSet bitset1 = BitSet.valueOf(new byte[] { 0, 1, 2, 3, 4, 5 });
      BitSet bitset2 = BitSet.valueOf(new byte[] { 2, 4, 6, 8, 10 });

      // print the sets
      System.out.println("Bitset1:" + bitset1);
      System.out.println("Bitset2:" + bitset2);

      // print the size of the sets
      System.out.println(bitset1.size());
      System.out.println(bitset2.size());
   }
}

Let us compile and run the above program, this will produce the following result −

Bitset1:{8, 17, 24, 25, 34, 40, 42}
Bitset2:{1, 10, 17, 18, 27, 33, 35}
64
64

Example 3

The following example shows the usage of Java BitSet size() method. We're creating two BitSets using long[] and using size() method we're printing the size of the bitsets.

package com.tutorialspoint;
import java.util.BitSet;
public class BitSetDemo {
   public static void main(String[] args) {

      // create 2 bitsets
      BitSet bitset1 = BitSet.valueOf(new long[] { 0, 1, 2, 3, 4, 5 });
      BitSet bitset2 = BitSet.valueOf(new long[] { 2, 4, 6, 8, 10 });

      // print the sets
      System.out.println("Bitset1:" + bitset1);
      System.out.println("Bitset2:" + bitset2);

      // print the size of the sets
      System.out.println(bitset1.size());
      System.out.println(bitset2.size());
   }
}

Let us compile and run the above program, this will produce the following result −

Bitset1:{64, 129, 192, 193, 258, 320, 322}
Bitset2:{1, 66, 129, 130, 195, 257, 259}
384
320