The mapToDouble() method returns a DoubleStream consisting of the results of applying the given function to the elements of this stream.The syntax is as follows.DoubleStream mapToDouble(IntToDoubleFunction mapper)Here, the parameter mapper is the stateless function applied to each element.Create an IntStream with some elements.IntStream intStream = IntStream.of(5, 20, 25, 45, 60, 75, 85, 90);Now, use the mapToDouble() method to return a DoubleStream.DoubleStream doubleStream = intStream.mapToDouble(val -> (double) val);The following is an example to implement IntStream mapToDouble() method in Java.Example Live Demoimport java.util.*; import java.util.stream.IntStream; import java.util.stream.DoubleStream; public class Demo {    public static void main(String[] args) {       IntStream intStream ... Read More

The equality of two Periods can be determined using the equals() method in the Period class in Java. This method requires a single parameter i.e. the Period object to be compared. Also it returns true if both the Period objects are equal and false otherwise.A program that demonstrates this is given as followsExample Live Demoimport java.time.Period; public class Demo {    public static void main(String[] args) {       String period1 = "P5Y7M15D";       Period p1 = Period.parse(period1);       String period2 = "P5Y7M15D";       Period p2 = Period.parse(period2);       System.out.println("The Period p1 ... Read More

The counting() method of the Java 8 Collectors class returns a Collector accepting elements of type T that counts the number of input elements.The syntax is as follows −static Collector counting()Here, the parameter −T − type of input elementsLong − This class value of the primitive type long in an objectTo work with Collectors class in Java, import the following package −import java.util.stream.Collectors;The following is an example to implement counting() method in Java 8 −Example Live Demoimport java.util.stream.Collectors; import java.util.stream.Stream; public class Demo {    public static void main(String[] args) {       Stream stream = Stream.of("25", "50", ... Read More

The peek() method of the ArrayBlockingQueue class returns the head of this queue or null if this queue is empty.The syntax is as follows.public E peek()To work with ArrayBlockingQueue class, you need to import the following package.import java.util.concurrent.ArrayBlockingQueue;The following is an example to implement peek() method of Java ArrayBlockingQueue class.Example Live Demoimport java.util.concurrent.ArrayBlockingQueue; public class Demo {    public static void main(String[] args) throws InterruptedException {       ArrayBlockingQueue q = new ArrayBlockingQueue(10);       q.add(200);       q.add(310);       q.add(400);       q.add(450);       q.add(500);       q.add(550);       ... Read More

An immutable copy of the Period object where some days are added to it can be obtained using the plusDays() method in the Period class in Java. This method requires a single parameter i.e. the number of days to be added and it returns the Period object with the added days.A program that demonstrates this is given as followsExample Live Demoimport java.time.Period; public class Demo {    public static void main(String[] args) {       String period = "P5Y7M15D";       Period p1 = Period.parse(period);       System.out.println("The Period is: " + p1);       Period p2 ... Read More

The allMatch() method in the DoubleStream class returns whether all elements of this stream match the provided predicate.The syntax is as follows −boolean allMatch(DoublePredicate predicate)Here, the argument predicate is a stateless predicate to apply to elements of this stream. The DoublePredicate is a predicate of one double-valued argument.To use the DoubleStream class in Java, import the following package −import java.util.stream.DoubleStream;Create DoubleStream and add some elements −DoubleStream doubleStream = DoubleStream.of(15.8, 28.7, 35.7, 48.1, 78.9);Now, check whether the condition is TRUE for elements of the stream −boolean res = doubleStream.allMatch(num -> num > 10); The following is an example to implement DoubleStream ... Read More

The allMatch() method in the LongStream class returns whether all elements of this stream match the provided predicate.The syntax is as follows.boolean allMatch(LongPredicate predicate)The parameter predicate is a stateless predicate to apply to elements of this stream. The LongPredicate represents a predicate of one long-valued argument.To use the LongStream class in Java, import the following package.import java.util.stream.LongStream;The following is an example to implement LongStream allMatch() method in Java.Example Live Demoimport java.util.stream.LongStream; public class Demo {    public static void main(String[] args) {       LongStream longStream = LongStream.of(100L, 150L, 200L, 300L, 400L, 500L);       boolean res = longStream.allMatch(a ... Read More

An Instant can be combined with a timezone to create a ZonedDateTime object using the atZone() method in the Instant class in Java. This method requires a single parameter i.e. the ZoneID and it returns the ZonedDateTime object.A program that demonstrates this is given as followsExample Live Demoimport java.time.*; public class Demo {    public static void main(String[] args) {       Instant i = Instant.parse("2019-01-13T18:35:19.00Z");       System.out.println("The Instant object is: " + i);       ZonedDateTime zdt = i.atZone(ZoneId.of("Australia/Melbourne"));       System.out.println("The ZonedDateTime object is: " + zdt);    } }OutputThe Instant object is: 2019-01-13T18:35:19Z ... Read More

The skip() method of the DoubleStream class in Java returns a stream consisting of the remaining elements of this stream after discarding the first numEle elements of the stream. The numEle is a parameter which you can set to skip any number of elements from the stream.The syntax is as follows −DoubleStream skip(long numEle)Here, numEle is the number of elements to skip. The leading elements are skipped.To use the DoubleStream class in Java, import the following package −import java.util.stream.DoubleStream;The following is an example to implement DoubleStream skip() method in Java −Example Live Demoimport java.util.stream.DoubleStream; public class Demo { ... Read More

The anyMatch() method of the LongStream class in Java returns whether any elements of this stream match the provided predicate.The syntax is as follows.boolean anyMatch(LongPredicate predicate)Here, the parameter predicate is the stateless predicate to apply to elements of this stream. The LongPredicate represents a predicate of one long-valued argument.To use the LongStream class in Java, import the following package.import java.util.stream.LongStream;The following is an example to implement LongStream anyMatch() method in Java.Example Live Demoimport java.util.stream.LongStream; public class Demo {    public static void main(String[] args) {       LongStream longStream = LongStream.of(100L, 150L, 200L, 300L, 400L, 500L);       boolean ... Read More