Import the following package for Calendar class in Java.import java.util.Calendar;Firstly, create a Calendar object and display the current date and time.Calendar calendar = Calendar.getInstance(); System.out.println("Current Date and Time = " + calendar.getTime());Now, let us increment the hours using the calendar.add() method and Calendar.HOUR_OF_DAY constant. Set a negative value since you want to decrease the hours.calendar.add(Calendar.HOUR_OF_DAY, +5);Example Live Demoimport java.util.Calendar; public class Demo {    public static void main(String[] args) {       Calendar calendar = Calendar.getInstance();       System.out.println("Current Date = " + calendar.getTime());       // Incrementing hours by 5       calendar.add(Calendar.HOUR_OF_DAY, +5);     ... Read More

Import the following package for Calendar class in Java.import java.util.Calendar;Firstly, create a Calendar object and display the current date and time.Calendar calendar = Calendar.getInstance(); System.out.println("Current Date and Time = " + calendar.getTime());Now, let us increment the hours using the calendar.add() method and Calendar.HOUR_OF_DAY constant.calendar.add(Calendar.HOUR_OF_DAY, +5);Example Live Demoimport java.util.Calendar; public class Demo {    public static void main(String[] args) {       Calendar calendar = Calendar.getInstance();       System.out.println("Current Date = " + calendar.getTime());       // Incrementing hours by 5       calendar.add(Calendar.HOUR_OF_DAY, +5);       System.out.println("Updated Date = " + calendar.getTime());    } }OutputCurrent Date ... Read More

Import the following package for Calendar class in Java.import java.util.Calendar;Firstly, create a Calendar object and display the current date.Calendar calendar = Calendar.getInstance(); System.out.println("Current Date = " + calendar.getTime());Now, let us subtract the days using the add() method and Calendar.DATE constant. Set a negative value here since we are decrementing.calendar.add(Calendar.DATE, -2);Example Live Demoimport java.util.Calendar; public class Demo {    public static void main(String[] args) {       Calendar calendar = Calendar.getInstance();       System.out.println("Current Date = " + calendar.getTime());       // Decrementing days by 2       calendar.add(Calendar.DATE, -2);       System.out.println("Updated Date = " + ... Read More

The maximum among three numbers can be found using an if else statement. A Java program that demonstrates this is given as follows.Example Live Demopublic class Example {    public static void main(String args[]) {       int num1 = 15;       int num2 = -5;       int num3 = 7;       if (num1 >= num2 && num1 >= num3)          System.out.println( num1 + " is the maximum number.");       else if (num2 >= num1 && num2 >= num3)          System.out.println( num2 + " is the ... Read More

To check if a string is null or empty in Java, use the == operator.Let’s say we have the following strings.String myStr1 = "Jack Sparrow"; String myStr2 = "";Let us check both the strings now whether they are null or empty. Result will be a boolean.res = (myStr1 == null || myStr1.length() == 0); res = (myStr2 == null || myStr2.length() == 0); Example public class Demo {    public static void main(String[] args) {       String myStr1 = "Jack Sparrow";       String myStr2 = "";       boolean res;       ... Read More

Firstly, we have considered the following two dates.SimpleDateFormat s = new SimpleDateFormat("yyyy-MM-dd"); Date d1 = s.parse("2018-10-15"); Date d2 = s.parse("2018-11-10");Now, use the compareTo() method to compare both the dates. The results are displayed on the basis of the return value.if (d1.compareTo(d2) > 0) {    System.out.println("Date1 is after Date2!");    } else if (d1.compareTo(d2) < 0) {       System.out.println("Date1 is before Date2!");    } else if (d1.compareTo(d2) == 0) {       System.out.println("Date1 is equal to Date2!");    } else {       System.out.println("How to get here?"); }Example Live Demoimport java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Date; public class ... Read More

Let’s say we have the following zip code.String zipStr = "12345";Now, set the following regular expression to match zip codes in America.String reg = "^[0-9]{5}(?:-[0-9]{4})?$";Example Live Demopublic class Demo {    public static void main(String[] args) {       String zipStr = "12345";       // regular expression       String reg = "^[0-9]{5}(?:-[0-9]{4})?$";       boolean res = zipStr.matches(reg);       System.out.println("Is it a valid zip code in US? "+res);    } }OutputIs it a valid zip code in US? True

Firstly, let us consider a string with quotesString originalStr = "\"Demo Text\"";Now, consider the following logic for the beginning quote.if (originalStr.startsWith("\"")) {    originalStr = originalStr.substring(1, originalStr.length()); }Now, consider the following logic for the ending quote.if (originalStr.endsWith("\"")) {    originalStr = originalStr.substring(0, originalStr.length() - 1); }Example Live Demopublic class Demo {    public static void main(String[] args) {       String originalStr = "\"Demo Text\"";       System.out.println("String with double quotes= "+originalStr);       if (originalStr.startsWith("\"")) {          originalStr = originalStr.substring(1, originalStr.length());       }       if (originalStr.endsWith("\"")) {       ... Read More

To shift left in a BigInteger, use the shiftLeft() method.The java.math.BigInteger.shiftLeft(int n) returns a BigInteger whose value is (this

To shift bits in a BigInteger, use the shiftLeft() or shiftRight() method.shiftLeft() methodThe java.math.BigInteger.shiftLeft(int n) returns a BigInteger whose value is (this > n). Sign extension is performed. The shift distance, n, may be negative, in which case this method performs a left shift. It computes floor(this / 2n).Example Live Demoimport java.math.*; public class Demo {    public static void main(String[] args) {       BigInteger one;       one = new BigInteger("25");       one = one.shiftRight(3);       System.out.println("Result: " +one);    } }OutputResult: 3