DoubleBuffer clear() methods in Java with Examples

The clear() method of java.nio.CharBuffer Class is used to clear this buffer. While clearing this buffer following changes are done:

• the position is set to zero
• the limit is set to the capacity
• the mark is discarded.

Syntax:

public final DoubleBuffer clear()

Return Value: This method returns this DoubleBuffer instance after clearing all the data from it.

Below are the examples to illustrate the clear() method:

Examples 1:

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

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

public class GFG {

    public static void main(String[] args)
    {

        try {

            double[] darr = { 2.5, 3.5, 4.5, 6.7 };

            // creating object of DoubleBuffer
            // and allocating size capacity
            DoubleBuffer db
                = DoubleBuffer.wrap(darr);

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

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

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

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

            // try to call clear() to restore
            // to the position at index 0
            // by discarding the mark
            db.clear();

            // display position
            System.out.println("position after reset: "
                               + db.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: 0

Examples 2:

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

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

public class GFG {

    public static void main(String[] args)
    {

        double[] carr = { 2.4, 105.4, 13.9, 23.45d };

        // creating object of DoubleBuffer
        // and allocating size capacity
        DoubleBuffer db = DoubleBuffer.wrap(carr);

        // try to set the position at index 3
        db.position(3);

        // display position
        System.out.println("position before clear: "
                           + db.position());

        // try to call clear() to restore
        // to the position at index 0
        // by discarding the mark
        db.clear();

        // display position
        System.out.println("position after clear: "
                           + db.position());
    }
}

Output:

position before clear: 3
position after clear: 0

Reference: https://docs.oracle.com/javase/9/docs/api/java/nio/DoubleBuffer.html#clear–