The java.util.BitSet.toByteArray() is an inbuilt method of BitSet class that is used to produce a new byte array containing all of the bits of the existing BitSet. As per the official documentation, this process works in the following way:
if, byte[] bytes = bit_set.toByteArray();
then, bytes.length == (bit_set.length()+7)/8 and,
bit_set.get(n) == ((bytes[n/8] & (1<<(n%8))) != 0)For all n < 8 * bytes.length
Syntax:
Bit_Set.toByteArray()
Parameter: The method does not take any parameters.
Return value: The method returns the set consisting of ByteArray representation of the elements of the given BitSet.
Below programs illustrate the working of java.util.BitSet.toByteArray() method:
Program 1:
// Java code to illustrate toByteArray()import java.util.*;  public class BitSet_Demo {    public static void main(String args[])    {        // Creating an empty BitSet        BitSet init_bitset = new BitSet();          // Use set() method to add elements into the Set        init_bitset.set(10);        init_bitset.set(20);        init_bitset.set(30);        init_bitset.set(40);        init_bitset.set(50);          // Displaying the BitSet        System.out.println("BitSet: " + init_bitset);          byte[] arr = init_bitset.toByteArray();        System.out.println("The byteArray is: " + arr);          // Displaying the byteArray        System.out.println("The elements in the byteArray :");        for (int i = 0; i < arr.length; i++)            System.out.print(arr[i] + ", ");    }} |
Output:
BitSet: {10, 20, 30, 40, 50}
The byteArray is: [B@232204a1
The elements in the byteArray :
0, 4, 16, 64, 0, 1, 4,
Program 2:
// Java code to illustrate toByteArray()import java.util.*;  public class BitSet_Demo {    public static void main(String args[])    {        // Creating an empty BitSet        BitSet init_bitset = new BitSet();          // Use set() method to add elements into the Set        init_bitset.set(48);        init_bitset.set(64);        init_bitset.set(15);        init_bitset.set(95);        init_bitset.set(105);        init_bitset.set(21);          // Displaying the BitSet        System.out.println("BitSet: " + init_bitset);          byte[] arr = init_bitset.toByteArray();        System.out.println("The byteArray is: " + arr);          // Displaying the byteArray        System.out.println("The elements in the byteArray :");        for (int i = 0; i < arr.length; i++)            System.out.print(arr[i] + ", ");    }} |
Output:
BitSet: {15, 21, 48, 64, 95, 105}
The byteArray is: [B@232204a1
The elements in the byteArray :
0, -128, 32, 0, 0, 0, 1, 0, 1, 0, 0, -128, 0, 2,
