The indexOf() method of the Ints class returns the index of the first appearance of the value target in array. The syntax is as follows −public static int indexOf(int[] arr, int target)Here, parameter arr is an array of int values and target is the value to be checked for first appearance.Let us now see an example −Exampleimport com.google.common.primitives.Ints; class Demo {    public static void main(String[] args) {       int[] arr = { 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 };       int index = Ints.indexOf(arr, 40);       if (index != ... Read More

Let’s say the following is our stream −Stream stream = Stream.of(50, 100, 200, 400, 800, 1000, 2000);Now, convert stream to an array using toArray() −Object[] objArr = stream.toArray(Object[] ::new);Following is the program to convert Stream to an Array in Java −Exampleimport java.util.*; import java.util.stream.*; import java.util.function.Function; public class Demo {    public static void main(String args[]) {       Stream stream = Stream.of(50, 100, 200, 400, 800, 1000, 2000);       Object[] objArr = stream.toArray(Object[] ::new);       System.out.println("Array = "+ Arrays.toString(objArr));    } }OutputArray = [50, 100, 200, 400, 800, 1000, 2000]

Let’s say the following is our Set with string values −Set set = new HashSet(); set.add("Laptop"); set.add("Mobile"); set.add("Tablet"); set.add("LCD"); set.add("LED");Now, let us convert it to List −List list = new ArrayList(set);Following is the program to convert Set to List in Java −Exampleimport java.util.*; import java.util.stream.*; public class Demo {    public static void main(String args[]) {       Set set = new HashSet();       set.add("Laptop");       set.add("Mobile");       set.add("Tablet");       set.add("LCD");       set.add("LED");       set.add("Desktop");       System.out.println("Set = " + set);       List ... Read More

Let’s say the following is our set of string −Set setStr = new HashSet(Arrays.asList("50", "100", "150", "200", "250", "300", "500"));Now, convert it to set of Integer −Set setInteger = setStr.stream().map(s -> Integer.parseInt(s)).collect(Collectors.toSet());ExampleFollowing is the program to convert set of String to set of Integer in Java −import java.util.*; import java.util.stream.*; public class Demo {    public static void main(String args[]) {       Set setStr = new HashSet(Arrays.asList("50", "100", "150", "200", "250", "300", "500"));       System.out.println("Set (String) = " + setStr);       Set setInteger = setStr.stream().map(s -> Integer.parseInt(s))          .collect(Collectors.toSet());     ... Read More

Let’s say the following is our Set of Integer −Set setInteger = new HashSet(Arrays.asList(100, 200, 300, 500, 600, 800, 1000));Now, let us convert this to Set of String −Set setStr = setInteger.stream().map(String::valueOf).collect(Collectors.toSet());ExampleFollowing is the program to convert set of Integer to Set of String in Java −import java.util.*; import java.util.stream.*; import java.util.function.Function; public class Demo {    public static void main(String args[]) {       Set setInteger = new HashSet(Arrays.asList(100, 200, 300, 500, 600, 800, 1000));       System.out.println("Set = " + setInteger);       Set setStr = setInteger.stream().map(String::valueOf).collect(Collectors.toSet());       System.out.println("New Set (String) = " ... Read More

Let’s say the following is our set of Integer −Set set = new HashSet(Arrays.asList(50, 100, 150, 200, 400, 600, 800, 1000, 1200, 1500));Now, convert it to Array of Integer −int[] arr = set.stream()    .mapToInt(Integer::intValue)    .toArray();ExampleFollowing is the program to convert set of Integer to Array of Integer in Java −import java.util.*; import java.util.stream.*; import java.util.function.Function; public class Demo {    public static void main(String args[]) {       Set set = new HashSet(Arrays.asList(50, 100, 150, 200, 400, 600, 800, 1000, 1200, 1500));       System.out.println("Set = " + set);       int[] arr = set.stream().mapToInt(Integer::intValue).toArray();       System.out.println("Array = "+ Arrays.toString(arr));    } }OutputSet = [400, 800, 1200, 50, 100, 150, 200, 600, 1000, 1500] Array = [400, 800, 1200, 50, 100, 150, 200, 600, 1000, 1500]

Let us first declare and initialize milliseconds value variable −long milliSeconds = 656478;Now, convert Milliseconds to Date format −DateFormat dateFormat = new SimpleDateFormat("dd MMM yyyy HH:mm:ss:SSS Z"); Date date = new Date(milliSeconds);Following is the program to convert Milliseconds to Date Format in Java −Exampleimport java.text.DateFormat; import java.text.SimpleDateFormat; import java.util.Date; public class Demo {    public static void main(String args[]) {       long milliSeconds = 656478;       DateFormat dateFormat = new SimpleDateFormat("dd MMM yyyy HH:mm:ss:SSS Z");       Date date = new Date(milliSeconds);       System.out.println(dateFormat.format(date));    } }Output01 Jan 1970 00:10:56:478 +0000

Here’s our List with string values −List myList = Arrays.asList("One", "Two", "Three", "Four", "Five");Now, let us convert this List to Stream −Stream s = myList.stream();Following is the program to convert List to Stream in Java −Exampleimport java.util.*; import java.util.stream.*; import java.util.function.Function; public class Demo {    public static void main(String args[]) {       List myList = Arrays.asList("One", "Two", "Three", "Four", "Five");       System.out.println("List: " + myList);       Stream s = myList.stream();       System.out.println("Stream (List to Stream) = " + Arrays.toString(s.toArray()));    } }OutputList: [One, Two, Three, Four, Five] Stream (List to Stream) ... Read More

Here’s our List of String −List listString = Arrays.asList("25", "50", "75", "100", "125", "150");Now, convert the list of string to list of integer −List listInteger = listString.stream().map(Integer::parseInt).collect(Collectors.toList());Following is the program to convert List of String to List of Integer in Java −Exampleimport java.util.*; import java.util.stream.*; import java.util.function.*; public class Demo {    public static void main(String[] args) {       List listString = Arrays.asList("25", "50", "75", "100", "125", "150");       System.out.println("List of String = " + listString);       List listInteger = listString.stream().map(Integer::parseInt)          .collect(Collectors.toList());       System.out.println("List of Integer (converted from ... Read More

Here’s our List of Integer −List listInteger = Arrays.asList(25, 50, 75, 100, 125, 150);Now, convert List of Integer to List of String −List listString = listInteger.stream()    .map(s -> String.valueOf(s))    .collect(Collectors.toList());Following is the program to convert List of Integer to List of String in Java −Exampleimport java.util.*; import java.util.stream.*; import java.util.function.*; public class Demo {    public static void main(String[] args) {       List listInteger = Arrays.asList(25, 50, 75, 100, 125, 150);       System.out.println("List of Integer = " + listInteger);       List listString = listInteger.stream()          .map(s -> String.valueOf(s))   ... Read More