What is the CharBuffer arrayOffset() method in Java?

The java.nio.CharBuffer is a class we can use to store a buffer of characters. The arrayOffset() method of this class returns the offset of the first element of the buffer inside the buffer’s backing array.

Declaration

The CharBuffer.arrayOffset() method is declared as follows:

buff.arrayOffset()

buff: The CharBuffer whose first element offset is required.

Return value

The CharBuffer.arrayOffest() method returns an int that is the offset of the first element of buff.

If the buffer is not backed by an accessible array, UnsupportedOperationException is thrown.

If the buffer is backed by an array but the array is read-only, ReadOnlyBufferException is thrown.

Code

Example 1

Consider the code snippet below, which demonstrates the use of the CharBuffer.arrayOffset() method.

import java.nio.*;
import java.util.*;
public class main {
   public static void main(String[] args) {
      int n1 = 5;
      try {
         CharBuffer buff1 = CharBuffer.allocate(n1);
         buff1.put('a');
         buff1.put('m');
         System.out.println("buff1: " + Arrays.toString(buff1.array()));
         
         int foo = buff1.arrayOffset();
         System.out.println("\nbuff1 array offset: " + foo);
         
      } catch (IllegalArgumentException e) {
         System.out.println("Error!!! IllegalArgumentException");
      } catch (ReadOnlyBufferException e) {
         System.out.println("Error!!! ReadOnlyBufferException");
      } catch (UnsupportedOperationException e) {
         System.out.println("Error!!! UnsupportedOperationException");
      }
   }
}

import java.nio.*;
import java.util.*;
public class main {
   public static void main(String[] args) {
      int n1 = 5;
      try {
         CharBuffer buff1 = CharBuffer.allocate(n1);
         buff1.put('a');
         buff1.put('m');
         System.out.println("buff1: " + Arrays.toString(buff1.array()));
         
         CharBuffer buff2 = buff1.asReadOnlyBuffer();
         
         int foo = buff2.arrayOffset();
         System.out.println("\nbuff2 array offset: " + foo);
         
      } catch (IllegalArgumentException e) {
         System.out.println("Error!!! IllegalArgumentException");
      } catch (ReadOnlyBufferException e) {
         System.out.println("Error!!! ReadOnlyBufferException");
      } catch (UnsupportedOperationException e) {
         System.out.println("Error!!! UnsupportedOperationException");
      }
   }
}