core java

Determine if an Object is of Primitive Type

1. Overview Sometimes we need to determine if an object is of primitive type, especially for wrapper primitive types. However, there are...

Convert an Array of Primitives to a List

1. Overview In this short tutorial, we'll show how to convert an array of primitives to a List of objects of the corresponding type....

Why are Local Variables Thread-Safe in Java

1. Introduction Before we introduced thread-safety, and how it can be achieved. In this article, we'll take a look at local variables and...

Escape Sequences in Java with Examples

In this tutorial, we will discuss what are escape sequences or escape characters, why we need escape sequence, what is the length of the...

Easy Ways to Write a Java InputStream to an OutputStream

1. Overview In this quick tutorial, we're going to learn how to write a Java InputStream to a Java OutputStream. We'll first use core functionality from Java 8 and Java 9. Then, we'll look at a couple of external...

Comparing Objects in Java

1. Introduction Comparing objects is an essential feature of object-oriented programming languages. In this tutorial, we're going look at some of the features of the Java language that allow us to compare objects....

Top 400 Java Interview Questions and Answers

Guide to the Number Class in Java

1. Overview In this tutorial, we'll discuss Java's Number class. First, we'll learn what the Number class does and what methods it contains. Then, we'll dive into the various implementations of this abstract class. 2....

The Java Headless Mode

1. Overview On occasion, we need to work with graphics-based applications in Java without an actual display, keyboard, or mouse, let's say, on a server or a container. In this short tutorial, we're going to learn about Java's headless mode to address this scenario. We'll also look at what we can do in headless mode and what we can't. 2. Setting up Headless Mode There are many ways we can set up headless mode in Java...

[Complete Java] Notes and Programs for Fundamental & Important Concepts of Java Programming & Development.

Suryakant-Bharti/Important-Java-Concepts [Complete Java] Notes and Programs for Fundamental & Important Concepts of Java Programming & Development. Users starred: 55Users forked: 32Users watching:...

New Java 13 Features

1. Overview September 2019 saw the release of JDK 13, per Java's new release cadence of six months. In this article, we'll take a look at the new features and improvements introduced in this version. 2. Preview...

Java 14: instanceOf Pattern Matching

JDK prepares to use pattern matching in future versions. In JDK 12 pattern matching has been implemented in switch expression. And the same is being implemented to instanceOf in JDK 14 as a preview feature. In java program, instanceof include logic that combines testing if an expression has a certain type, and then conditionally extracting components of its state for further processing. if(obj instanceof Person){ ...

Bitwise & vs Logical && Operators

1. Introduction In Java, we've got two ways to say “AND”. But which to use? In this tutorial, we'll look at the differences between & and &&. And, we'll learn about bitwise operations and...

Using the Not Operator in If Conditions in Java

1. Introduction In Java's if-else statements we can take a certain action when an expression is true, and an alternative when it is false. In this tutorial, we'll learn about how to reverse the logic using the not...

Java for loop

Java for loop and enhanced for loop is a type of control flow statement which provides a compact way to iterate over a range of values. for loop repeatedly loops through the code until a particular condition is...

Switch case statement in Java

A switch statement is a conditional statement that tests against multiple cases and displays one or multiple outputs based on the matching circumstances. Unlike if-then and if-then-else statements, the switch statement can work with byte, short, char, and int primitive data types. It also works with enum types (discussed in Java Enum), the String class, and a few wrapper classes: Character, Byte, Short,...

Find the Smallest Missing Integer in an Array

1. Overview In this tutorial, we'll see different algorithms allowing us to find the smallest missing positive integer in an array. First, we'll go through the explanation of the problem. After that, we'll see three...

Java 12 new features

Most Common Features of Java 12 Switch expressions (JEP 325) Java 12 has enhanced Switch expressions for Pattern matching. It extends the switch statement so that it can be used as either a statement or an expression. These Forms can be used either as a “traditional” or “simplified” scoping control flow behavior. Thus the benefits are, these changes are used for simplification of everyday coding, for preparing the way, use...

java 11 new features

As the virtual machine is moving forward and updating quickly, so, at an interval of every six months, Java introduces a new version release to cope with the rate of new technology innovation. The three latest versions...

Causes & Avoidance of java.lang.VerifyError

1. Introduction In this tutorial, we'll look at the cause of java.lang.VerifyError errors and multiple ways to avoid it. 2. Cause The Java Virtual Machine (JVM) distrusts all loaded bytecode as a core tenet of the...

Converting Java Date to OffsetDateTime

1. Introduction In this tutorial, we learn about the difference between Date and OffsetDateTime. We also learn how to convert from one to the other. 2. Difference between Date and OffsetDateTime OffsetDateTime was...

Data types in Java

Java is a statically-typed language, which means that all variables must first be declared before they can be used. It means the variable’s name and types must be defined before it can be used in code. boolean bool = true; By writing the above line we are telling the program that a variable named bool of type boolean is created, which has the default value as true. Java has 8 types of primitive data types. Different Primitive...