Java: Most Popular Articles
Learn how to generate random numbers using the java.util.Random class.
The use of variables is key to any program. Learn how to declare and initialize variables in Java.
Throughout the lifetime of a variable its value might change many times. But what if you know the value will never change? Or more importantly you want to make sure it can't change? This is when you need to use a constant.
Cannot Find Symbol is a compile-time error.
This program creates a simple calculator that performs addition and subtraction. It highlights how to implement the ActionListener interface in three different ways.
An example Java class for building a simple GUI application. This program corresponds to the Coding a Simple Graphical User Interface - Part I
In object-oriented programming sometimes it's necessary to provide access to the private fields of an object. The use of accessors and mutators are a way to enable that access.
Are you ready to start programming in Java? Follow this step-by-step tutorial to learn how to write, compile and run Java programs. Page 2.
When a new instance of an object is created the constructor method is called. Examples of how to create constructor methods in Java are discussed here.
Using standard Java naming conventions will increase the readability of your code and make it easier to maintain.
Follow these steps if you want to find out if your computer is 32-bit or 64-bit.
How to use JFrame to create a simple window for a Java application.
Find out what Java is, who created it, and why people choose to program with it.
Follow this step-by-step guide to learn how to design and create an object. Page 6.
Example Java program code for how to make simple message dialog boxes using the JOptionPane class.
Use the if-then and if-then-else statements when your program needs to make a simple decision about what to do next.
An example program showing how to use the JTable class
Static methods are created using the static keyword.
Here you will find a list of words that you cannot use as identifiers in a Java program.
Aggregation is a relationship between two objects that is best described as a
A method signature is part of the method declaration. It is the combination of the method name and the parameter list.
An identifier is simply a name given to a package, class, interface, method, or variable.
An example program showing how to implement the KeyListener interface.
Example Java program code to make several different types of input dialog boxes using the showInputDialog method of JOptionPane.
Learn how to use the JOptionPane class to make a simple message dialog box
Fields can be shared across all objects of the same type through the use of the static modifier.
An example Java program showing how to use the JProgressBar
Follow this step-by-step tutorial to learn how to write, compile and run Java applets.
There are three different types of exceptions a Java application might encounter.
Learn about the Unicode standard, a global way to encode the characters that computers use.
How to make use of command-line arguments in your Java applications.
Make your first Java download the right one. Step-by-Step instructions on how to download the latest version of the JDK.
Reached end of file while parsing is a compile time error.
Enhance the readability of your programs by using Java comments.
How to convert Strings to numbers and back again.
OpenJDK is an open source version of the JDK.
If you're new to programming and want to find out what it's like to use an IDE, this is the guide for you. Learn how to write a simple Hello NetBeans World program using the NetBeans IDE.
Example Java program code for creating a simple password dialog box.
The ternary operator ?: earns its name because it's the only operator to take three operands.
Sometimes the random numbers to be picked need to be unique.
The association relationship is a way of describing the fact that a class knows about, and holds a reference to another class.
A step-by-step guide to manually coding a simple graphical user interface. Part two of this step-by-step shows how to code the same graphical user interface using NetBeans Gui Builder.
Find out how to use the showInputDialog method of the JOptionPane class to make different kinds of input dialog boxes.
An example JavaFX application to show how to build a simple graphical user interface. The interface is the same as those built using Swing in part 1 and NetBeans GuiBuilder in part two.
The void keyword denotes that a method does not have a return type.
A Java program to show the String class in action.
Learn about object inheritance and how it can be used to create a relationship between objects that share common characteristics.
The Java language provides eight primitive data types that define simple values a program can use.
Verify if a file or directory exists or if can it be accessed by the application
See if you can debug a piece of code that produces one of the most fundamental Java runtime errors.
A subclass is a class that extends another class.
An example program to show the DefaultTableModel in action.
Learn how to include the functionality of packaged classes into your programs.
A look at the JTable class and how it can be used to make simple tables for GUIs
A simple application showing how the CardLayout can be used to switch JPanels.
How to implement the Key Listener Interface, which provides the ability to find out what keys a user is pressing while a graphical component has the focus of the graphical user interface.
Bring a sense of order to your classes through the use of packages.
Example Java code to show how the GridLayout, the BorderLayout and the BoxLayout can be used to make a customizable graphical user interface for a simple calculator.
A variable is a container that holds values that are used in a Java program.
In a method call the implicit parameter is the object the method belongs to.
String Literals are used for representing string values in Java code.
Scope refers to the lifetime and accessibility of a variable. How large the scope is depends on where a variable is declared.
An object is an instance of a class.
Following on from the first article on generating random numbers in Java, find out how to generate random fractional numbers and boolean values.
Conditional operators are used to evaluate a condition that's applied to one or two boolean expressions.
A look at how to use the GridLayout layout manager.
Example code for reading and writing to a binary file one byte at a time.
How to use the ArrayList class. Java.
Understanding object-oriented programming is fundamental to becoming a truly great Java programmer. The key concepts of objects are discussed in this article.
Concatenation describes the operation of joining two strings together.
Example code showing how the GridBagLayout layout manager can be used to position components.
Declaration statements are used to declare variables.
A superclass is a class that has been extended by another class.
A class specifies the design of an object.
This example code shows how to simply switch between two JavaFX stylesheets.
A clever German mathematician created a simple formula that will produce what is sometimes known as the hailstone sequence. Can you write a program to display that sequence for a certain number?
Turtles, magic and squares will conspire to test your logic in this exercise.
An example Java program showing a simple application using the BoxLayout.
When coding in Java it's important to remember that Java is case sensitive. Here are some tips to avoid common case sensitivity pitfalls.
Compound assignment operators provide a shorter syntax to assign the results of the arithmetic and bitwise operators.
Step-by-Step instructions on how to install the latest version of the JDK.
How to delete, copy and move files using nio.2
The ActionListener interface is an event listener for actions performed by some graphical components.
How to make use of arrays. Java.
An example Java application which allows the user to combine various JOptionPane options to show example dialog boxes.
Before you start to learn Java, you need somewhere to write your programs. Here's a guide to using an IDE versus a text editor.
Example Java program code to show how the JFileChooser class is used to present an open file dialog box and save file dialog box to a user.
Use the switch statement when you want your program to chose between a number of alternative options.
This step-by-step guide shows how to build the simple GUI application created in Coding a Simple Graphical User - Part I using the NetBeans GUI Builder.
An example program to show how to code a BorderLayout layout manager with assigned horizontal and vertical spacing.
A basic look at the structure of a very simple Java program. This article gives a beginner a starting place for understanding the way the Java syntax builds to make a Java program.
Learn how to read bytes from a binary file one byte at a time.
An event listener receives and process events.
How to create a simple JavaFX FXML application using NetBeans and Scene Builder.
NetBeans is a sophisticated IDE that aims to help developers build any type of application.
Example Java code showing the ItemListener event listener in action
Java handles exception through the use of the try-catch-finally blocks
A constant is a variable whose value cannot change once it has been assigned.
The main method is the starting point for the execution of every Java application.
The denary (or decimal) numbering system is the most widely used in the world. It has a base of 10 and uses the numerals 0,1,2,3,4,5,6,7,8,9.
Parameters are the variables that are listed as part of a method declaration.
An overview of the BorderLayout layout manager.
Some classes are designed not to be extended by other classes. Find out how to prevent a class being inherited by another.
Whilst learning Java the best way is to compile and run example code. Using multiple classes within a NetBeans project means you can keep all your code examples in one place and try them out independently of each other.
Find out about data encapsulation, the most important concept of object-oriented programming.
Example Java code showing how the TreeView JavaFX control is used.
Java 7 Update 45 has been released and the JDK is available to download from Oracle's Java download page. The release notes show this to be a security fix
Example Java code for a program which provides a user with options to change the alignment and spacing of components in a FlowLayout layout manager.
Can you rewrite this Java code so that there is no longer an infinite loop?
Competition in the Robocode arena is fierce. Learn Java by trying to build a robot that will send all the others to the scrap heap!
If expressions are akin to clauses in the English language, then statements are like sentences.
Things are a little different for Java developers on Mac OS X. Find out how Java fits in with Apple computers.
Java is a strongly typed programming language because every variable must be declared with a data type.
A relational operator compares two operands to determine whether one is greater than, greater than or equal to, less than, less than or equal to the other.
A common question new developer are faced with, is where do I start when faced with learning the Java language? Here are some tips.
An overview of how to use the GridPane to make a table format.
A look at the table model behind the JTable
Overloading is the ability to define more than one method with the same name in a class.
An example of how to use the JavaFX BorderPane layout
An example program showing how to implement the three mouse event listeners
The term composition takes on different meanings depending on the subject, and in Java it has its own meaning as well.
A look at the JavaFX ComboBox class.
An event typically occurs when a user interacts with a user interface.
Constructor chaining occurs through the use of inheritance.
An overview of the Adopt a JSR program
Hexadecimal refers to a numbering system that has a base of 16. This means it uses all the numerals 0,1,2,3,4,5,6,7,8,9 as well as the letters A,B,C,D,E,F for each digit of a number.
java.lang.NoClassDefFoundError is a runtime error.
Example Java code showing how the ListView and ComboBox JavaFX controls can be used.
A literal is a value that can be written directly into Java source code.
Discover how a class can inherit the state and behaviors of another class.
It’s a way of designing an application that separates data access, business logic and the graphical user interface.
Any application providing a secure environment for a user needs to be able to safely obtain the password for that user.
Example Java program code that shows the two static methods of the JColorChooser class in action to make a color chooser dialog box.
Loops are a way of executing the same code block many times.
The String class lets you create and manipulate Strings.
Building an interface for a simple calculator program
When a new version of an API is released it's quite common for parts of it to become deprecated.
See how to create a message dialog box when you want the user to confirm a message with a Yes or OK.
A step-by-step by guide implementing the MouseListener, MouseMotionListener, and MouseWheelListener event listeners using a simple gui application.
Java technology recognizes that developers build different applications based on the differing needs of their users. Discover the different editions of the Java platform available to developers.
The most commonly used operator is the assignment operator.
Expressions are essential building blocks of any Java program. They are built using values, variables, operators and method calls.
The string class provides a few methods for manipulating Strings.
Here are the steps to disable (or enable) the Java plugin in a browser.
Find out what an exception is and how Java handles them.
How to use the GridPane layout to place child nodes in a grid format.
Arithmetic operators perform the same basic operations you would expect if you used them in mathematics (with the exception of the percentage sign).
Garbage collection frees up memory that is no longer in use.
How to make a progress bar using the JProgressBar class
The float data type in Java can be used to store floating point numbers.