Found 4336 Articles for Java 8

Create integer array with Array.newInstance in Java

Nancy Den
Updated on 25-Jun-2020 13:13:53

153 Views

The java.lang.reflect.Array.newInstance(Class componentType, int length) method forms a new array with the component type and length as specified in the argumentsDeclaration − The java.lang.reflect.Array.newInstance(Class componentType, int length) method is declared as follows -public static Object newInstance(Class componentType, int length) throws IllegalArgumentException, NegativeArraySizeExceptionLet us see a program to create an integer array with Array.newInstance with Java Reflection -Example Live Demoimport java.lang.reflect.Array; public class Example {    public static void main(String[] args) {       int[] arr = (int[]) Array.newInstance(int.class, 3); // creates a new array       Array.set(arr, 0, 5);       Array.set(arr, 1, 9);       Array.set(arr, ... Read More

Create array with Array.newInstance with Java Reflection

Krantik Chavan
Updated on 25-Jun-2020 13:14:40

105 Views

The java.lang.reflect.Array.newInstance(Class componentType, int length) method forms a new array with the component type and length as specified in the argumentsDeclaration − The java.lang.reflect.Array.newInstance(Class componentType, int length) method is declared as follows −public static Object newInstance(Class componentType, int length) throws IllegalArgumentException, NegativeArraySizeExceptionLet us see a program to create array with Array.newInstance with Java Reflection −Example Live Demoimport java.lang.reflect.Array; public class Example {    public static void main(String[] args) {       String[] arr = (String[]) Array.newInstance(String.class, 3); // creates a new array       Array.set(arr, 0, "A");       Array.set(arr, 1, "B");       Array.set(arr, 2, "C"); ... Read More

Determining If an Object Is an Array in Java

Anvi Jain
Updated on 29-Jun-2020 06:38:56

5K+ Views

In order to determine if an object is an Object is an array in Java, we use the isArray() and getClass() methods.The isArray() method checks whether the passed argument is an array. It returns a boolean value, either true or falseSyntax - The isArray() method has the following syntax -Array.isArray(obj)The getClass() method method returns the runtime class of an object. The getClass() method is a part of the java.lang.Object class.Declaration − The java.lang.Object.getClass() method is declared as follows −public final Class getClass()The getClass() method acts as the intermediate method which returns an runtime class of the object, which enables the terminal ... Read More

How to schedule tasks in Java to run for repeated fixed-rate execution, beginning after the specified delay

Smita Kapse
Updated on 29-Jun-2020 06:39:50

298 Views

One of the methods of the Timer class is void scheduleAtFixedRate(TimerTask task, long delay, long period). This method schedules the specified task for repeated fixed-rate execution, beginning after the specified delay.In fixed-rate execution, each execution is scheduled with respect to the scheduled run time of the initial execution. Fixed-rate execution is apt for repetitive activities that are respond to absolute time. Likewise, fixed-rate execution is appropriate for scheduling multiple repeating timer tasks that must remain in sync.Declaration − The java.util.Time.scheduleAtFixedRate(TimerTask task, long delay, long period) method is declared as follows −public void scheduleAtFixedRate(TimerTask task, long delay, long period)Here, task is ... Read More

Get Array Dimensions in Java

Nancy Den
Updated on 29-Jun-2020 06:41:04

1K+ Views

In order to get Array Dimensions in Java, we use the getClass(), isArray() and getComponentType() methods with decision making in combination with iterative statements.The getClass() method method returns the runtime class of an object. The getClass() method is a part of the java.lang.Object class.Declaration − The java.lang.Object.getClass() method is declared as follows −public final Class getClass()The isArray() method checks whether the passed argument is an array. It returns a boolean value, either true or falseSyntax - The isArray() method has the following syntaxArray.isArray(obj)The getComponentType() method returns the Class denoting the component type of an array. If the class is not an ... Read More

Get array upperbound in Java Multidimensional Arrays

Krantik Chavan
Updated on 25-Jun-2020 13:18:03

468 Views

In order to get the array upperbound of a multidimensional array, we use the length() method. For a 2D array, the length() method returns the number of rows. We can access the number of columns using the array_name[0].length method.Let us see a program to get the array upperbound in Java Multidimensional arraysExample Live Demopublic class Example {    public static void main(String args[]) {       String[][] str = new String[5][10];       System.out.println("1st dimension : " + str.length); // displays the number of rows       System.out.println("2nd dimension : " + str[0].length); // displays the number of columns    } }Output1st dimension : 5 2nd dimension : 10

Create and demonstrate an immutable collection in Java

Anvi Jain
Updated on 29-Jun-2020 06:41:47

138 Views

In order to create and demonstrate an immutable collection in Java, we use the unmodifiableCollection() method. This method returns an unmodifiable and immutable view of the collection.Declaration − The java.util.Collections.unmodifiableCollection() method is declared as follows -public static Collection unmodifiableCollection(Collection

Sort items of an ArrayList with Collections.reverseOrder() in Java

Smita Kapse
Updated on 25-Jun-2020 13:19:27

358 Views

In order to sort items of an ArrayList with Collections.reverseOrder() in Java, we need to use the Collections.reverseOrder() method which returns a comparator which gives the reverse of the natural ordering on a collection of objects that implement the Comparable interface.Declaration − The java.util.Collections.reverseOrder() method is declared as follows -public static Comparator reverseOrder()Let us see a program to sort an ArrayList with Collections.reverseOrder() in Java -Example Live Demoimport java.util.*; public class Example {    public static void main (String[] args) {       ArrayList list = new ArrayList();       list.add(10);       list.add(50);       ... Read More

Rotate elements of a collection in Java

Nancy Den
Updated on 25-Jun-2020 13:19:58

305 Views

To rotate elements of a collection in Java, we use the Collections.rotate() method. The rotate method rotates the elements specified in the list by a specified distance. When this method is invoked, the element at index x will be the element previously at index (x - distance) mod list.size(), for all values of i between 0 and list.size()-1, inclusive.Declaration − The java.util.Collections.rotate() is declared as follows -public static void rotate(List list, int distance)Let us see a program to rotate elements of a collection in Java -Example Live  Demoimport java.util.*; public class Example {    public static void main(String[] args) {   ... Read More

Java Program to fill elements in a long array

Krantik Chavan
Updated on 25-Jun-2020 13:20:30

232 Views

Elements can be filled in a long array using the java.util.Arrays.fill() method. This method assigns the required long value to the long array in Java. The two parameters required are the array name and the value that is to be stored in the array elements.A program that demonstrates this is given as follows -Example Live Demoimport java.util.Arrays; public class Demo {    public static void main(String[] argv) throws Exception {       long[] longArray = new long[5];       long longValue = 125;       Arrays.fill(longArray, longValue);       System.out.println("The long array content is: " + Arrays.toString(longArray)); ... Read More

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