You are here
Home > java > Core Java (Page 5)

Core Java

Interview Questions for Object Oriented Programming

by devs5003 - 2

OOP (Object Oriented Programming) concepts are the essential & the most important concepts in any Object Oriented Programming Language. Any exam or interview of an OOP language is considered incomplete without these questions. Therefore, it becomes crucial to practice them thoroughly time to time. Certainly, we will be talking about the practice test of OOP concepts in this article. It helps in thorough revision of the subject and make the concept crystal clear. Here in this article, we will focus on Interview Questions for Object Oriented Programming in the form of MCQs Practice Test with a variety of questions such as concept-based, code-based, and scenario-based. At the end of each question, we will explore the detailed explanation of each question. In

Optional Class in Java 8 – A Comprehensive Tutorial

by devs5003 - 2

Java 8 introduced many significant features, one of which is the Optional class. It was intended to address the common problem of dealing with null values in Java. Many people in the industry feel that you are not a real Java programmer until you haven't come across a NullPointerException. Since NullPointerException indicates the absence of a value, the null reference is the source of many problems. So, Optional class can address some of these problems. In this article, we will explore the Optional Class in Java 8, its benefits, usage, and best practices to ensure efficient and null-safe code. What is Optional Class in Java? The Optional is a class of the 'java.util' package. In simple words, Optional is a single-value container/wrapper that

Java 23 New Features With Examples

by devs5003 - 1

Java Development Kit 23, the next version of Java Standard Edition, is now available as a production release on September 17, 2024. Java 23 comes with various new features, some preview features, incubator feature, deprecation & deletions. It is inclined to improve developer productivity and program efficiency. In this article, we will explore some of the most essential developer’s friendly Java 23 new features with examples. You may also go through the LTS version Java 21 New Features With Examples. Java 23 New Features With Examples Let's start exploring Java 23 New Features with examples one by one. Primitive Types in Patterns, instanceof, and switch (Preview) – JEP 455 This is a preview language feature. Till Java 22, instanceof cannot be used with primitive data

MCQ on SOLID Principles Practice Test

by devs5003 - 0

One of the best ways to become an expert in any subject is by practicing it in a regular interval. There are many ways to practice the subject. It totally depends on you. In my opinion, solving the practice test is the most prominent way to refresh your concept without going through the theory & concepts again. When you start solving the practice test, all your old concepts gets recalled. In this article, we will explore SOLID Principles Practice Test in the form of MCQs, including a mix of concept-based, code-based, and scenario-based questions. After each question, we will go over the explanation for why each option is right or wrong. Don’t overlook the incorrect options, as they might recap other

Default Method in Interface

by devs5003 - 0

As we are aware that till JDK 7 we couldn't include implemented method inside an interface. In other words, there was no provision to have a method body inside a method of an Interface. But for those who are reading Default Methods for the first time it will be very surprising. The surprise is that we can now include an implemented method inside an Interface. Therefore, we can also have an implemented method inside an interface. Here, we are talking about default method in interface. The most use of default method in interface is to provide additional functionality to a given type without breaking down the existing implemented classes. In this article, we are going to take a deeper look on

Static Methods In Interface

by devs5003 - 2

Before learning the Static Methods in Interface let's go back to JDK 7 and older versions, and memorize the scope of a static method. We will come to a conclusion that Static Methods could be defined in a class, abstract class, final class but not in an interface. However, from JDK 8 onward, we can define Static Methods in Interface as well. Now you might have one question 'What is the need of defining Static methods in Interface?'. Wait for a couple of minutes, you will get to know each & every concept behind it. In this article we will have a closer look on the 'Static Methods in Interface'. Furthermore, we will also talk about main() method as the main()

Java 8 Features

by devs5003 - 4

Java 8 was released by Oracle after 2 Years 7 Months 18 Days of release of java 7 on March 18th, 2014.  However, after Java 1.5 version, Java 8 is the next major release version. Before Java 8, Sun community focused majorly on objects, but in Java 8 version, Oracle community has focused more on functional programming to bring its benefits to the Java language. However, it doesn’t mean that Java is a functional oriented programming language, but we should grasp it in a way that we can apply functional aspects of programming as well now with Java 8. It is a part of Java 8, as an object oriented programming. Here, we will discuss new Java 8 Features one by

How to Extract Text from Image Using Java?

by devs5003 - 1

Many a times we come across a requirement when we need to extract text from image. This process is also known as Optical Character Recognition (OCR). OCR is extensively useful in various use cases, such as converting physical documents into digital formats to make them searchable and editable, automating data entry processes to minimize errors, extracting information from checks in banking institutions, digitizing patient records in the healthcare industry, converting case files into digital formats in the legal department, digitizing textbooks, extracting information from invoices, receipts, and many more. This article will focus on How to Extract Text from Image Using Java?. Although there are many online image-to-text converter tools are introduced that can extract text from image automatically, but knowing

Annotations In Java

by devs5003 - 5

Before the introduction of Annotations, we were extensively using XML for metadata. Using XML for metadata as configurations separates the configuration from the code. At the later stage, when enterprise applications grown up, maintenance of XML was getting inconvenienced. Also, XML loosely couples from the code, in some cases almost separates. Then architects & developers started looking for solutions which can be tightly coupled with the code instead of XML. Then the solution was an introduction to Annotations. Don't get confused with the fact that we should always prefer loose coupling as it differs in case of Annotations. You will feel the benefits almost always when you completely understand the topic 'Annotations In Java'. Just using an annotation instead of creating

Continuation-Passing Style-CPS in Java

by devs5003 - 0

Continuation-Passing Style (CPS) is a programming model used to manage control flow in software applications. It provides a way to handle asynchronous or callback-based programming by explicitly passing control from one function to another. Although this concept was originally generalized in functional programming languages like Scheme, Haskell, and Scala, but CPS can also be implemented in object-oriented languages like Java. In this article, we'll analyze the concepts behind Continuation-Passing Style-CPS in Java and explore its implementation with code examples. What is Continuation-Passing Style? In traditional programming model, control flow is managed through the call stack. When a function is called, the current execution context is pushed onto the stack, and when the function returns, the context is popped off the stack, allowing

Top