Programming Articles - Page 3317 of 3366

What is a method signature in Java?

Swarali Sree
Updated on 30-Jul-2019 22:30:20

7K+ Views

The method signature consists of the method name and the parameter list. Example Live Demo public class MethodSignature { public int add(int a, int b){ int c = a+b; return c; } public static void main(String args[]){ MethodSignature obj = new MethodSignature(); int result = obj.add(56, 34); System.out.println(result); } } Output 90 Method ... Read More

How to create and write JSON array to a file in java?

Abhinaya
Updated on 19-Feb-2020 12:26:38

4K+ Views

Java provides javax.json.Json package which contains classes to read a JSON array:Exampleimport java.io.FileOutputStream; import javax.json.Json; import javax.json.JsonArray; import javax.json.JsonWriter; public class JSONArrayToFile {    public static void main(String args[]) throws Exception {       JsonArray value = Json.createArrayBuilder()          .add(Json.createObjectBuilder()          .add("id", "1001")          .add("Technology", "JavaFX"))          .add(Json.createObjectBuilder()          .add("id", "1002")          .add("Technology", "OpenCV"))          .build();       System.out.println(value);       JsonWriter writer = Json.createWriter(new FileOutputStream("sampleData"));       writer.writeArray(value);       writer.close();    } }Output["JavaFX","HBase","JOGL","WebGL"] After deleting ::["JavaFX","HBase","JOGL"]

What is the super class of every class in Java?

Alshifa Hasnain
Updated on 28-Feb-2025 18:48:15

6K+ Views

The Object class is the superclass of every single class in Java. This position implies that every class in Java, even if a built-in class or function like String or a user-defined one, directly or indirectly inherits from Object. Understanding the Object Class The Object class provides fundamental methods that every Java object inherits. Even if a class does not explicitly extend another class, it implicitly extends Object. Below is a demostration of the same − class Example { //This class implicitly extends to an Object } Why Does Every Class Inherit from ... Read More

How to remove a specific element from a JSON Array in Java?

Govinda Sai
Updated on 19-Feb-2020 12:25:46

15K+ Views

You can remove an element from the JSONArray object using the remove() method. This method accepts an integer and removes the element in that particular index.Exampleimport org.json.JSONArray; public class RemoveFromJsonArray {    public static void main(String args[]) throws Exception {       String [] myArray = {"JavaFX", "HBase", "JOGL", "WebGL"};       JSONArray jsArray = new JSONArray();       for (int i=0; i < myArray.length; i++) {          jsArray.put(myArray[i]);      }      System.out.println(jsArray);      jsArray.remove(3);      System.out.println("After deleting ::"+jsArray);    } }Output["JavaFX","HBase","JOGL","WebGL"] After deleting ::["JavaFX","HBase","JOGL"]

Can a final class be subclassed in Java?

Alshifa Hasnain
Updated on 27-Feb-2025 19:28:35

2K+ Views

In Java Inheritance is a fundamental feature that allows a class to derive properties and behaviors from another class. In Java, not all classes can be subclassed. A final class is a special type of class that cannot be extended.  What is a Final Class in Java? In Java, a class is declared final using the final keyword. The final modifier for finalizing the implementations of classes, methods, and variables. When a class is marked as final, it means − It cannot be extended. All its methods remain unchanged in their ... Read More

How do I get the parent directory in Python?

Niharikaa Aitam
Updated on 29-Apr-2025 19:11:23

3K+ Views

In Python, when working with files and directories, we may often need to access the parent directory of a given path, especially when going through a file system or managing relative paths in a project. In this article, we are going to explore the different methods available in Python to get the parent directory of the current or any specific path. Using os Module One of the commonly used methods to interact with the file system in Python is using the os module. This module provides various utilities to work with file paths and directories. To get the parent directory, ... Read More

How to convert JSON Array to normal Java Array?

Ramu Prasad
Updated on 19-Feb-2020 12:24:47

3K+ Views

The get method of the JSONArray class returns the element at a particular index. Using this method, you can get the elements of the JSONArray object and populate the array with them.Exampleimport java.util.Arrays; import org.json.JSONArray; public class JsonToArray {    public static void main(String args[]) throws Exception {       String [] myArray = {"JavaFX", "HBase", "JOGL", "WebGL"};       JSONArray jsArray = new JSONArray();       for (int i = 0; i < myArray.length; i++) {          jsArray.put(myArray[i]);      }      System.out.println(jsArray);      String[] array = new String[myArray.length];   ... Read More

How to convert Java Array/Collection to JSON array?

Sravani S
Updated on 30-Jul-2019 22:30:20

8K+ Views

Google provides a library named org.json.JSONArray and, following is the maven dependency to add library to your project. com.googlecode.json-simple json-simple 1.1 The JSONArray class of the org.json package provides put() method. Using this method, you can populate the JSONArray object with the contents of the elements.Exampleimport org.json.JSONArray; public class ArrayToJson { public static void main(String args[]) { String [] myArray = {"JavaFX", "HBase", "JOGL", "WebGL"}; JSONArray jsArray = new JSONArray(); ... Read More

How to perform binary search on an array in java?

V Jyothi
Updated on 16-Jun-2020 10:17:11

207 Views

The Arrays class of java package provides you a method named binarySearch() using this method you can perform a binary search on an array in Java.ExampleLive Demoimport java.util.Arrays; public class ArrayDemo {    public static void main(String[] args) {       int intArr[] = {30,20,5,12,55};       Arrays.sort(intArr);       System.out.println("The sorted int array is:");       for (int number : intArr) {          System.out.println("Number = " + number);       }       int searchVal = 12;       int retVal = Arrays.binarySearch(intArr,searchVal);       System.out.println("The index of element 12 is : " + retVal);    } }OutputThe sorted int array is: Number = 5 Number = 12 Number = 20 Number = 30 Number = 55 The index of element 12 is: 1

How to perform heapsort on an array in Java?

Priya Pallavi
Updated on 19-Feb-2020 12:22:49

694 Views

Following is the algorithm for heapsort (maxheap).Step 1 − Create a new node at the end of the heap.Step 2 − Assign new value to the node.Step 3 − Compare the value of this child node with its parent.Step 4 − If the value of parent is less than a child, then swap them.Step 5 − Repeat step 3 & 4 until Heap property holds.Exampleimport java.util.Arrays; import java.util.Scanner; public class Heapsort {    public static void heapSort(int[] myArray, int length) {       int temp;       int size = length-1;       for (int i ... Read More

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