CharBuffer mark() methods in Java with Examples

The mark() method of java.nio.CharBuffer Class is used to set this buffer's mark at its position. Syntax:

public CharBuffer mark()

Return Value: This method returns this buffer. Below are the examples to illustrate the mark() method: Examples 1:

Java

// Java program to demonstrate
// mark() method

import java.nio.*;
import java.util.*;

public class GFG {

    public static void main(String[] args)
    {

        try {

            char[] carr = { 'a', 'b', 'c', 'd' };

            // creating object of CharBuffer
            // and allocating size capacity
            CharBuffer cb = CharBuffer.wrap(carr);

            // try to set the position at index 2
            cb.position(2);

            // Set this buffer mark position
            // using mark() method
            cb.mark();

            // try to set the position at index 4
            cb.position(4);

            // display position
            System.out.println("position before reset: "
                               + cb.position());

            // try to call reset() to restore
            // to the position we marked
            cb.reset();

            // display position
            System.out.println("position after reset: "
                               + cb.position());
        }

        catch (InvalidMarkException e) {
            System.out.println("new position is less than "
                               + "the position we marked before ");
            System.out.println("Exception throws: " + e);
        }
    }
}

Output:

position before reset: 4
position after reset: 2

Examples 2: To demonstrate InvalidMarkException

Java

// Java program to demonstrate
// mark() method

import java.nio.*;
import java.util.*;

public class GFG {

    public static void main(String[] args)
    {

        try {

            char[] carr = { 'a', 'b', 'c', 'd' };

            // creating object of CharBuffer
            // and allocating size capacity
            CharBuffer cb = CharBuffer.wrap(carr);

            // try to set the position at index 2
            cb.position(2);

            // Set this buffer mark position
            // using mark() method
            cb.mark();

            // try to set the position at index 4
            cb.position(1);

            // display position
            System.out.println("position before reset: "
                               + cb.position());

            // try to call reset() to restore
            // to the position we marked
            cb.reset();

            // display position
            System.out.println("position after reset: "
                               + cb.position());
        }

        catch (InvalidMarkException e) {
            System.out.println("\nnew position is less than "
                               + "the position we marked before ");
            System.out.println("Exception throws: " + e);
        }
    }
}

Output:

position before reset: 1

new position is less than the position we marked before 
Exception throws: java.nio.InvalidMarkException

Reference: https://docs.oracle.com/javase/9/docs/api/java/nio/CharBuffer.html#mark--

CharBuffer mark() methods in Java with Examples

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