BigInteger class provides operations for modular arithmetic, GCD calculation, primality testing, prime generation, bit manipulation, and a few other miscellaneous operations.Let’s say the following is our byte array −byte[] arr = new byte[] { 0x1, 0x00, 0x00 };We will now convert them to BigInteger −BigInteger bInteger = new BigInteger(arr);The following is an example that creates BigInteger from a byte array in Java.Example Live Demoimport java.math.BigInteger; public class Demo {    public static void main(String[] argv) throws Exception {       byte[] arr = new byte[] { 0x1, 0x00, 0x00 };       BigInteger bInteger = new BigInteger(arr);       System.out.println(bInteger);    } }Output65536

BigInteger class is used for big integer calculations which are outside the limit of the primitive data types. It provides operations for modular arithmetic, GCD calculation, primality testing, prime generation, bit manipulation, and a few other miscellaneous operations.Firstly, set a long value −Long l = 198L;Now, create a new object for BigInteger and pass the above value −BigInteger bInteger = new BigInteger(l);The following is an example −Example Live Demoimport java.math.BigInteger; public class Demo {    public static void main(String[] argv) throws Exception {       Long l = 198L;       BigInteger bInteger = BigInteger.valueOf(l);       System.out.println(bInteger);    } }Output198

BigInteger class is used for big integer calculations which are outside the limit of the primitive data types. It provides operations for modular arithmetic, GCD calculation, primality testing, prime generation, bit manipulation, and a few other miscellaneous operations.Firstly, set a string −String str = "268787878787687";Now, create a new object for BigInteger and pass the above string −BigInteger bInteger = new BigInteger(str);The following is an example −Example Live Demoimport java.math.BigInteger; public class Demo {    public static void main(String[] argv) throws Exception {       String str = "268787878787687";       BigInteger bInteger = new BigInteger(str);       System.out.println(bInteger);    } }Output268787878787687

Enum in Java contains a fixed set of constants. They can have fields, constructors and method. It enhances type safety in Java.The following is an example wherein we are implementing Switch statement on Enumeration in Java −Example Live Demopublic class Demo {    public static void main(String[] args) {       Laptop l = Laptop.Inspiron;       switch(l){          case Inspiron:          System.out.println("Laptop for home and office use!");             break;          case XPS:           System.out.println("Laptop for the ultimate experience!");             break;          case Alienware:           System.out.println("Laptop for high-performance gaming");             break;       }    } } enum Laptop {       Inspiron, XPS, Alienware; }OutputLaptop for home and office use!

We can use the == operator to compare enums in Java.Let’s say we have the following enum.enum Devices {    LAPTOP, MOBILE, TABLET; }Here are some of the objects and we have assigned some values as well −Devices d1, d2, d3; d1 = Devices.LAPTOP; d2 = Devices.LAPTOP; d3 = Devices.TABLET;Let us now see an example wherein we will compare them using == operator −Example Live Demopublic class Demo {    enum Devices {       LAPTOP, MOBILE, TABLET;    }    public static void main(String[] args) {       Devices d1, d2, d3;       d1 = Devices.LAPTOP; ... Read More

To compare enumeration values, use the equals() method.Our Devices enum is having some objects with values assigned to them.Devices d1, d2, d3; d1 = Devices.LAPTOP; d2 = Devices.LAPTOP; d3 = Devices.TABLET;Let us compare them −if(d3.equals(Devices.TABLET)) System.out.println("Devices are same."); else System.out.println("Devices are different.");The following is an example −Example Live Demopublic class Demo {    enum Devices {       LAPTOP, MOBILE, TABLET;    }    public static void main(String[] args) {       Devices d1, d2, d3;       d1 = Devices.LAPTOP;       d2 = Devices.LAPTOP;       d3 = Devices.TABLET;       if(d1.equals(d2))   ... Read More

We have the Devices Enum with four constants.enum Devices { LAPTOP, MOBILE, TABLET, DESKTOP; }We have created some objects and assigned them with the constants.Let us compare them with both equals() and ==. Firstly, begin with equals() −if(d1.equals(d2)) System.out.println("Devices are the same."); else System.out.println("Devices are different.");Now, let us move forward and check for ==if(d1 == d3) System.out.println("Devices are the same."); else System.out.println("Devices are different.");The following is the final example demonstrating both equals() and == operator −Example Live Demopublic class Demo {    enum Devices {       LAPTOP, MOBILE, TABLET, DESKTOP;    }    public static void main(String[] args) { ... Read More

To set enum for days of the week, set them as constantsenum Days { Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday }Now create objects and set the above constants −Days today = Days.Wednesday; Days holiday = Days.Sunday;The following is an example −Example Live Demopublic class Demo {    enum Days {       Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday    }    public static void main(String[] args) {       Days today = Days.Wednesday;       Days holiday = Days.Sunday;       System.out.println("Today = " + today);       System.out.println(holiday+ " is holiday");    } }OutputToday = Wednesday Sunday is holiday

Firstly, set the day of year using DAY_OF_YEAR constant.Calendar cal = Calendar.getInstance(); cal.set(Calendar.YEAR, 2018); cal.set(Calendar.DAY_OF_YEAR, 320);Now, get the day of month −int res = cal.get(Calendar.DAY_OF_MONTH);The following is an example −Example Live Demoimport java.util.Calendar; public class Demo {    public static void main(String[] args) {       Calendar cal = Calendar.getInstance();       cal.set(Calendar.YEAR, 2018);       cal.set(Calendar.DAY_OF_YEAR, 320);       System.out.println("Date = " + cal.getTime());       int res = cal.get(Calendar.DAY_OF_MONTH);       System.out.println("Day of month = " + res);    } }OutputDate = Fri Nov 16 07:54:55 UTC 2018 Day of month = 16Read More

To get the days remaining in the current year, find the difference between the total days in the current year with the total number of days passed.First, calculate the day of year.Calendar calOne = Calendar.getInstance(); int dayOfYear = calOne.get(Calendar.DAY_OF_YEAR);Now, calculate the total days in the current year 2018.int year = calOne.get(Calendar.YEAR); Calendar calTwo = new GregorianCalendar(year, 11, 31); int day = calTwo.get(Calendar.DAY_OF_YEAR); System.out.println("Days in current year: "+day);The following is the final example that finds the difference between the above two to get the days remaining in the current year.ExampleLive Demoimport java.util.Calendar; import java.util.GregorianCalendar; public class Demo {    public static ... Read More