Let’s say the following is our Iterator with Integer values −Iteratoriterator = Arrays.asList(20, 40, 60, 80, 100, 120, 150, 200).iterator();Now, convert the Iterator to Iterable −Iterableiterable = StreamSupport.stream(Spliterators.spliteratorUnknownSize(iterator, 0),false).collect(Collectors.toList());ExampleFollowing is the program to convert Iterator to Iterable in Java −import java.util.*; import java.util.stream.Collectors; import java.util.stream.StreamSupport; public class Demo {    public static void main(String[] args) {       Iteratoriterator = Arrays.asList(20, 40, 60, 80, 100, 120, 150, 200).iterator();       Iterableiterable = StreamSupport.stream(Spliterators.spliteratorUnknownSize(iterator, 0), false).collect(Collectors.toList());       System.out.println("Iterable = ");       iterable.forEach(System.out::println);    } }OutputIterable = 20 40 60 80 100 120 150 200

In this article, we will learn to convert a HashSet to a TreeSet in Java. Converting from one type of collection to another is a simple process when we require them to change their behavior or the nature of our data structure. Why Convert HashSet to TreeSet? For the following operations, we can convert a HashSet to a TreeSet − Sorted Order: TreeSet maintains elements in ascending order. Range-Based Operations: It supports operations like headSet(), tailSet(), and subSet(). NavigableSet Features: TreeSet provides methods like higher(), lower(), ceiling(), ... Read More

At first, initialize a double value −double val = 978.65;Now, convert the Double to Integer value using intValue() method −Double d = new Double(val); int res = d.intValue();ExampleFollowing is the program to convert Double to Integer in Java −public class Demo {    public static void main(String args[]) {       double val = 978.65;       System.out.println("Double = "+val);       Double d = new Double(val);       int res = d.intValue();       System.out.println("Double to Integer value = "+res);    } }OutputDouble = 978.65 Double to Integer value = 978

At first, set an Interator −Iteratoriterator = Arrays.asList(50, 100, 200, 400, 500, 1000).iterator();Now, we have used stream −Streamstream = convertIterator(iterator);Above, the method convertIterator() is used for conversion. Following is the method −public static Stream convertIterator(Iterator iterator) {    return StreamSupport.stream(((Iterable) () -> iterator).spliterator(), false); }ExampleFollowing is the program to convert an Iterator to Stream in Java −import java.util.stream.*; import java.util.*; public class Demo {    public static Stream    convertIterator(Iterator iterator) {       return StreamSupport.stream(((Iterable) () -> iterator).spliterator(), false);    }    public static void main(String[] args) {       Iteratoriterator = Arrays.asList(50, 100, 200, ... Read More

Let us first create a set with string values −Setset = new HashSet(Arrays.asList("One", "Two", "Three", "Four", "Five", "Six"));Now, convert it to a comma separated string using String.join() −String str = String.join(", ", set);ExampleFollowing is the program to convert set of string to a comma separated string in Java −import java.util.*; public class Demo {    public static void main(String args[]) {       Setset = new HashSet(Arrays.asList("One", "Two", "Three", "Four", "Five", "Six"));       System.out.println("Set = " + set);       String str = String.join(", ", set);       System.out.println("Comma separated String: "+ str);    } ... Read More

At first, let’s say the following is our List of String −List myList = new ArrayList(Arrays.asList("One", "Two", "Three", "Four"));Now, convert this to a comma separated string using String.join()String str = String.join(", ", myList);ExampleFollowing is the program to convert List of String to a comma separated String in Java −import java.util.*; public class Demo {    public static void main(String args[]) {       List myList = new ArrayList(Arrays.asList("One", "Two", "Three", "Four"));       System.out.println("List = " + myList);       // comma separated       String str = String.join(", ", myList);       System.out.println("String (Comma ... Read More

At first, let us create a Java Map and initialize −Map map = new HashMap(); map.put(1, "Tom"); map.put(2, "John"); map.put(3, "Kevin"); map.put(4, "Jacob"); map.put(5, "Ryan");Now, convert the Map to List −ArrayList key = new ArrayList(map.keySet()); ArrayList value = new ArrayList(map.values());ExampleFollowing is the program to convert Maps to List in Java −import java.util.HashMap; import java.util.ArrayList; import java.util.Map; public class Demo {    public static void main(String args[]) {       Map map = new HashMap();       map.put(1, "Tom");       map.put(2, "John");       map.put(3, "Kevin");       map.put(4, "Jacob");       map.put(5, "Ryan"); ... Read More

Let’s say the following is our string −String str = "My String";Now, convert the above to IntStream −IntStream stream = str.chars();ExampleFollowing is the program to convert String to IntStream in Java −import java.util.stream.IntStream; public class Demo {    public static void main(String[] args) {       String str = "My String";       System.out.println("String: " + str);       IntStream stream = str.chars();       System.out.println("IntStream...");       stream.forEach(System.out::println);    } }OutputString: My String IntStream... 77 121 32 83 116 114 105 110 103

Let’s first create an IntStream −IntStream stream = "Ryan".chars();Now, convert this IntStream to String −String str = stream.collect(StringBuilder::new,StringBuilder::appendCodePoint,StringBuilder::append).toString();ExampleFollowing is the program to convert IntStream to String in Java −import java.util.stream.IntStream; public class Demo {    public static void main(String[] args) {       IntStream stream = "Ryan".chars();       String str =stream.collect          (StringBuilder::new,StringBuilder::appendCodePoint,StringBuilder::append).toString();       System.out.println("String (IntStream to string) = " + str);    } }OutputString (IntStream to string) = Ryan

At first create a HashMap −Map map = new HashMap(); map.put("1", "One"); map.put("2", "Two"); map.put("3", "Three"); map.put("4", "Four"); map.put("5", "Five"); map.put("6", "Six");Now, convert the above HashMap to TreeMap −Map treeMap = new TreeMap(); treeMap.putAll(map);ExampleFollowing is the program to convert HashMap to TreeMap in Java −import java.util.*; import java.util.stream.*; public class Demo {    public static void main(String args[]) {       Map map = new HashMap();       map.put("1", "One");       map.put("2", "Two");       map.put("3", "Three");       map.put("4", "Four");       map.put("5", "Five");       map.put("6", "Six");       ... Read More