How do I use the shift right “>>” operator?

By Wayan in Basic, Core API 0 Comment

The signed shift right operator >> shifts a bit pattern to the right. This operator operates with two operand, the left-hand operand to be shifted and the right-hand operand tells how much position to shift.

Shifting a 1000 bit pattern using the >> operator 2 position will produce a 0010 bit pattern. The signed shift right operator produce a result that equals to dividing a number by 2.

package org.kodejava.basic;

public class SignedRightShiftOperator {
    public static void main(String[] args) {
        // The binary representation of 32 is
        // "00000000000000000000000000100000"
        int number = 32;
        System.out.println("number       = " + number);
        System.out.println("binary       = " +
                Integer.toBinaryString(number));

        // Using the shift right operator we shift the bits
        // four times to the right which resulting the result
        // of "00000000000000000000000000000010"
        int shiftedRight = number >> 4;
        System.out.println("shiftedRight = " + shiftedRight);
        System.out.println("binary       = " +
                Integer.toBinaryString(shiftedRight));
    }
}

The result of the code snippet:

number       = 32
binary       = 100000
shiftedRight = 2
binary       = 10

How do I use the shift left “<<" operator?

By Wayan in Basic, Core API 2 Comments

The signed shift left operator << shifts a bit pattern to the left. This operator operates with two operand, the left-hand operand to be shifted and the right-hand operand tells how much position to shift.

Shifting a 0010 bit pattern using the << operator 2 position will produce a 1000 bit pattern. The signed shift left operator produce a result that equals to multiplying a number by 2, which double the value of a number.

package org.kodejava.basic;

public class SignedLeftShiftOperator {
    public static void main(String[] args) {
        // The binary representation of 2 is "0010"
        int number = 2;
        System.out.println("number      = " + number);
        System.out.println("binary      = " +
                Integer.toBinaryString(number));

        // Using the shift left operator we shift the bits two
        // times to the left. This will shift the "0010" into
        // "1000"
        int shiftedLeft = number << 2;
        System.out.println("shiftedLeft = " + shiftedLeft);
        System.out.println("binary      = " +
                Integer.toBinaryString(shiftedLeft));
    }
}

The result of the code snippet:

number      = 2
binary      = 10
shiftedLeft = 8
binary      = 1000

How do I use the unary bitwise complement “~” operator?

By Wayan in Basic, Core API 0 Comment

The unary bitwise complement operator (~) inverts a bit pattern; it can be applied to any of the integral types, making every 0 a 1 and every 1 a 0.

For example, an integer contains 32 bits; applying this operator to a value whose bit pattern is 00000000000000000000000000001000 would change its pattern to 11111111111111111111111111110111.

package org.kodejava.basic;

public class UnaryBitwiseComplementOperator {
    public static void main(String[] args) {
        // An integer type contains 32 bit information.
        // 8 = 00000000000000000000000000001000
        int number = 8;
        System.out.println("number = " + number);
        System.out.println(Integer.toBinaryString(number));

        // Using the ~ operator inverts the number by change the
        // every "0" to "1" and every "1" to "0".
        // 00000000000000000000000000001000
        // 11111111111111111111111111110111
        //
        int invertedNumber = ~number;
        System.out.println("invertedNumber = " + invertedNumber);
        System.out.println(Integer.toBinaryString(invertedNumber));
    }
}

The result of the code snippet:

number = 8
1000
invertedNumber = -9
11111111111111111111111111110111

How do I remove elements from Deque?

By Wayan in Core API, Util Package 0 Comment

This example shows you how to remove some elements from the Deque object. We can use the following methods for removing elements from Deque: remove(), remove(Object o), removeFirst(), removeLast().

package org.kodejava.util;

import java.util.Deque;
import java.util.LinkedList;

public class RemoveDequeDemo {
    public static void main(String[] args) {
        Deque<String> deque = new LinkedList<>();
        deque.add("A");
        deque.add("B");
        deque.add("C");
        deque.add("D");
        deque.add("E");
        deque.add("F");

        // Removes and retrieves the head of this Deque
        deque.remove();      // Removes "A"

        // Removes the first occurrence of element from this Deque
        deque.remove("F");   // Removes "F"

        // Retrieves and removes the first element of this deque
        deque.removeFirst(); // Removes "B"

        // Retrieves and removes the last element of this deque
        deque.removeLast();  // Removes "E"

        for (String item : deque) {
            System.out.println("Item = " + item);
        }
    }
}

How do I add elements into a Deque?

By Wayan in Core API, Util Package 0 Comment

To add elements into a Deque object we can use the add(), addFirst() and addLast() method call.

package org.kodejava.util;

import java.util.Deque;
import java.util.LinkedList;

public class DequeAddElement {
    public static void main(String[] args) {
        // Create an instance of Deque using LinkedList class.
        Deque<String> deque = new LinkedList<>();

        // Insert a word into the Deque
        deque.add("jumps");

        // Insert words at the beginning of the current Deque
        // elements
        deque.addFirst("fox");
        deque.addFirst("brown");
        deque.addFirst("quick");
        deque.addFirst("The");

        // Insert words at the end of the current Deque elements
        deque.addLast("over");
        deque.addLast("the");
        deque.addLast("lazy");
        deque.addLast("dog");

        for (String word : deque) {
            System.out.println("Word = " + word);
        }
    }
}

Here is the output:

Word = The
Word = quick
Word = brown
Word = fox
Word = jumps
Word = over
Word = the
Word = lazy
Word = dog