Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
Programming Articles
Page 1541 of 2547
When will be an object eligible for garbage collection?
Java Garbage collector tracks the live object and objects which are no more need are marked for garbage collection. It relieves developers to think of memory allocation/deallocation issues.When an object created in Java program is no longer reachable or used it is eligible for garbage collection.Following are some scenarios where a Java object could be unreachable/unused.Object inside a method − In Java a method is stored in the stack memory. When you call a method, JVM fetches it into the stack and executes it. After the execution it is popped out of the stack then, all its variables will be ...
Read MoreConvert a Vector to an array in Java
A Vector can be converted into an Array using the java.util.Vector.toArray() method. This method requires no parameters and it returns an Array that contains all the elements of the Vector in the correct order.A program that demonstrates this is given as follows −Exampleimport java.util.Vector; public class Demo { public static void main(String args[]) { Vector vec = new Vector(); vec.add(7); vec.add(3); vec.add(5); vec.add(2); vec.add(8); Object[] arr = vec.toArray(); System.out.println("The Array elements are: "); ...
Read MoreHow to import all classes in Java?
All the classes in a package can be imported using the import statement along with the character *. For example - All the classes in the package java.util can be imported using import java.util.*;A program that demonstrates this in Java is given as follows:Exampleimport java.util.*; public class Demo { public static void main(String args[]) { Stack stack = new Stack(); stack.push("Apple"); stack.push("Mango"); stack.push("Guava"); stack.push("Pear"); stack.push("Orange"); System.out.println("The stack elements are: " + stack); } }OutputThe stack elements are: ...
Read MoreLongStream asDoubleStream() method in Java
The asDoubleStream() method of the LongStream class in Java returns a DoubleStream consisting of the elements of this stream, converted to double.The syntax is as follows.DoubleStream asDoubleStream()Here, DoubleStream is a sequence of primitive double-valued elements. To use the LongStream class in Java, import the following package.import java.util.stream.LongStream;Create LongStream and add elements.LongStream longStream = LongStream.of(2000L, 35000L, 45000L);Now, convert it to double and return using asDoubleStream() method.DoubleStream s = longStream.asDoubleStream();The following is an example to implement LongStream asDoubleStream() method.Exampleimport java.util.stream.LongStream; import java.util.stream.DoubleStream; public class Demo { public static void main(String[] args) { LongStream longStream = LongStream.of(2000L, 35000L, 45000L); ...
Read MoreCan we declare an abstract method final or static in java?
A method which does not have body is known as abstract method. It contains only method signature with a semi colon and, an abstract keyword before it.public abstract myMethod();To use an abstract method, you need to inherit it by extending its class and provide implementation to it.Declaring abstract method staticIf you declare a method in a class abstract to use it, you must override this method in the subclass. But, overriding is not possible with static methods. Therefore, an abstract method cannot be static.If you still, try to declare an abstract method static a compile time error is generated saying ...
Read MoreJava Program to create an array with randomly shuffled numbers in a given range
For randomly shuffled numbers, let us create an integer list and add some numbers −List < Integer > list = new ArrayList < Integer > (); list.add(10); list.add(50); list.add(100); list.add(150); list.add(200);Now, shuffle the elements for random values −Collections.shuffle(list);Create an int array with the same number of elements in the above list −intlen = list.size(); int[] res = newint[len];Set the shuffled values in the new array −for (inti = 0; i < len; i++) { res[i] = list.get(i); }Exampleimport java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.List; public class Demo { public static void main(String args[]) { ...
Read MoreCan a constructor throw an exception in Java?
Yes, constructors are allowed to throw an exception in Java.A Constructor is a special type of a method that is used to initialize the object and it is used to create an object of a class using the new keyword, where an object is also known as an Instance of a class. Each object of a class will have its own state (Instance variables) and access to methods of its class.Throw an Exception from a ConstructorA checked exception can be used to indicate a legitimate problem when trying to create an instance, while an unchecked exception typically indicates a bug either in the ...
Read MoreHow to randomize and shuffle array of numbers in Java?
At first, create an integer array −int[] arr = { 20, 40, 60, 80, 100, 120, 140, 160, 180, 200};Now, create a Random class object −Random rand = new Random();Loop until the length of the array and shuffle the elements −for (int i = 0; i < arr.length; ++i) { int index = rand.nextInt(arr.length - i); int tmp = arr[arr.length - 1 - i]; arr[arr.length - 1 - i] = arr[index]; arr[index] = tmp; }Exampleimport java.util.Arrays; import java.util.Random; public class Demo { public static void main(String[] args) { int[] arr = { ...
Read MoreLongStream limit() method in Java
The limit() method of the LongStream class in Java returns a stream consisting of the elements of this stream, truncated to be no longer than max in length. Here, max is the parameter of the method.The syntax is as follows.LongStream limit(long max)Here, max is the number of elements the stream should be limited to.To use the LongStream class in Java, import the following package.import java.util.stream.LongStream;Create a LongStream and add elements.LongStream longStream = LongStream.of(2000L, 35000L, 45000L, 50500L, 65000L, 72000L);Now, let’s say you only want to return 4 elements. For that, use the limit as 4.longStream.limit(4).The following is an example to implement ...
Read MoreHow to shuffle an array in Java?
Declare a string array and add elements in the form of letters −String[] letters = { "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z" };Convert the above array to list −Listlist = Arrays.asList(letters);Now, create a shuffled array using the Random class object and generate the random letters with nextInt() −int len = list.size(); System.out.println("Shuffled array..."); for (int i = 0; i < letters.length; i++) { int index = new Random().nextInt(len); String shuffle = list.get(index); System.out.println(shuffle); }Exampleimport java.util.Arrays; import java.util.List; import java.util.Random; public class Demo { public static void main(String[] args) { ...
Read More