JavaWorld Core Java

• Sorting with Comparable and Comparator in Java August 22, 2019
  Programmers frequently need to sort elements from a database into a collection, array, or map. In Java, we can implement whatever sorting algorithm we want with any type. Using the Comparable interface and compareTo() method, we can sort using alphabetical order, String length, reverse alphabetical order, or numbers. The Comparator interface allows us to do […]
• Thread behavior in the JVM August 22, 2019
  Threading refers to the practice of executing programming processes concurrently to improve application performance. While it's not that common to work with threads directly in business applications, they're used all the time in Java frameworks.As an example, frameworks that process a large volume of information, like Spring Batch, use threads to manage data. Manipulating threads […]
• Method overloading in the JVM August 22, 2019
  Welcome to the new Java Challengers blog! This blog is dedicated to challenging concepts in Java programming. Master them and you will be well on your way to becoming a highly skilled Java programmer.The techniques in this blog take some effort to master, but they’ll make a great difference in your daily experience as a […]
• String comparisons in Java August 22, 2019
  In Java, the String class encapsulates an array of char. Put simply, String is an array of characters used to compose words, sentences, or any other data you want.Encapsulation is one of the most powerful concepts in object-oriented programming. Because of encapsulation, you don’t need to know how the String class works; you just need […]
• Polymorphism and inheritance in Java August 22, 2019
  According to the legend Venkat Subramaniam, polymorphism is the most important concept in object-oriented programming. Polymorphism--or the ability of an object to execute specialized actions based on its type--is what makes Java code flexible. Design patterns like Command, Observer, Decorator, Strategy, and many others created by the Gang Of Four, all use some form of […]
• Comparing Java objects with equals() and hashcode() August 15, 2019
  In this Java Challenger you’ll learn how equals() and hashcode() combine to make object comparisons efficient and easy in your Java programs. Simply put, these methods work together to verify if two objects have the same values.  Without equals() and hashcode() we would have to create very large "if" comparisons, comparing every field from an […]
• Debugging Java inheritance July 23, 2019
  Inheritance and composition are two programming techniques developers use to establish relationships between classes and objects. Whereas inheritance derives one class from another, composition defines a class as the sum of its parts.Classes and objects created through inheritance are tightly coupled because changing the parent or superclass in an inheritance relationship risks breaking your code. […]
• Interfaces in Java July 16, 2019
  Java interfaces are different from classes, and it's important to know how to use their special properties in your Java programs. This tutorial introduces the difference between classes and interfaces, then guides you through examples demonstrating how to declare, implement, and extend Java interfaces.You'll also learn how the interface has evolved in Java 8, with […]
• Class and object initialization in Java July 9, 2019
  Classes and objects in Java must be initialized before they are used. You've previously learned that class fields are initialized to default values when classes are loaded and that objects are initialized via constructors, but there is more to initialization. This article introduces all of Java's features for initializing classes and objects. download Get the […]
• Java polymorphism and its types May 30, 2019
  Polymorphism refers to the ability of some entities to occur in different forms. It is popularly represented by the butterfly, which morphs from larva to pupa to imago. Polymorphism also exists in programming languages, as a modeling technique that allows you to create a single interface to various operands, arguments, and objects. Java polymorphism results […]