Programming Articles - Page 2576 of 3363

In the Real time world javascript doesn't have traditional classes as seen in other languages. It has objects and constructors. Object.freeze() is one among many constructor methods helps to freeze an object.Freezing an object does not allow new properties to be added to the object and also prevents the object from changing its own properties. Object.freeze() will always try to preserve the enumerability, configurability, writability and the prototype of the object. It won't create a frozen copy.Applications1) freeze() is used for freezing objects and arrays.2) freeze() is used to make an object immutable.SyntaxObject.freeze(obj)ExampleLive Demo // an object is created ... Read More

Yes, we can declare an abstract class with no abstract methods in Java. An abstract class means that hiding the implementation and showing the function definition to the user. An abstract class having both abstract methods and non-abstract methods. For an abstract class, we are not able to create an object directly. But Indirectly we can create an object using the subclass object. A Java abstract class can have instance methods that implement a default behavior. An abstract class can extend only one class or one abstract class at a time. Declaring a class as abstract with no abstract methods means that we don't allow it ... Read More

Interfaces in Java are used for defining a contract that classes can implement. They can contain method signatures, default methods, static methods, and constants. we must implement the methods defined in the interface in the implementing class. Constructor in an Interface A Constructor is to initialize the non-static members of a particular class with respect to an object. An Interface in Java doesn't have a constructor because all data members in interfaces are public static final by default, they are constants (assign the values at the time of declaration). There are ... Read More

Differences between Mean.io and Mean.jsThe MEAN is a stack framework. When combined with Mongodb, node.js, express.js and angular.js it helps to create a complete javascript web app. A software developer from Israel, Amos Haviv was the first person to initiate Mean.io. Mean.js is simply a fork out from Mean.io. When developers closely observe these two variations they perceive that Mean.io has a different objective than Mean.js. The only reason might be that Mean.io is not as elegant as Mean.js. When a developer completely understands Stack, mostly he prefers Mean.js.Let's look where Mean.io and Mean.js differ1) Boilerplate generation and scaffoldingThese are ... Read More

In a PHP application, we are working with data in various formats such as string, array, objects or more...In a real-time application, we may need to read a php object result in the form of an associative array to get the desired output.So we will discuss here how to transform a php object to an associative array in PHP.Let's explain what is an object and associative array in PHP? An object is an instance of a class meaning that from one class you can create many objects. It is simply a specimen of a class and has memory allocated. While ... Read More

An interface cannot implement another interface in Java. An interface in Java is essentially a special kind of class. Like classes, the interface contains methods and variables. Unlike classes, interfaces are always completely abstract. An interface is defined just like a class except for the keyword interface in place of a class, the variables are declared in an interface are static and final and the methods are defined in an interface are public abstract methods. An interface can extend any number of interfaces but one interface cannot implement another interface, because if any interface is implemented then its methods must be defined and ... Read More

To check whether a node is a root node or not, use the isRoot() method. This returns a boolean value. TRUE if the node is a root node, else FALSE is returned. For example, TRUE is returned since the following node is a root node −node.isRoot()Another example, FALSE is returned since the following node isn’t a root node −node2.isRoot()The following is an example to check whether a node is a root node or not −Examplepackage my; import javax.swing.JFrame; import javax.swing.JTree; import javax.swing.tree.DefaultMutableTreeNode; public class SwingDemo {    public static void main(String[] args) throws Exception {       JFrame frame ... Read More

The matte border gives a “matte” look. Let’s say the following is our component −JLabel label; label = new JLabel("This has matte border!");Let us create a matte border with BorderFactory class. Here, we have given color YELLOW using the Color class −label.setBorder(BorderFactory.createMatteBorder(3, 5, 10, 5, Color.YELLOW));The following is an example to create a Matte-look border −Examplepackage my; import javax.swing.BorderFactory; import java.awt.Color; import java.awt.Font; import javax.swing.JFrame; import javax.swing.JLabel; public class SwingDemo {    public static void main(String[] args) throws Exception {       JFrame frame = new JFrame("Demo");       JLabel label;       label = new JLabel("This ... Read More

The etched border gives an ‘etched’ look. Let’s say the following is our component −JLabel label; label = new JLabel("This has etched border with an 'etched' look!");Let us create an etched border with BorderFactory class −label.setBorder(BorderFactory.createEtchedBorder());The following is an example to create etched border for a component using BorderFactory class −Examplepackage my; import javax.swing.BorderFactory; import java.awt.Font; import javax.swing.JFrame; import javax.swing.JLabel; public class SwingDemo {    public static void main(String[] args) throws Exception {       JFrame frame = new JFrame("Demo");       JLabel label;       label = new JLabel("This has etched border with an 'etched' look!"); ... Read More

To enable multiple selections in a JFileChooser dialog, use the setMultiSelectionEnabled() to be TRUE −JFileChooser file = new JFileChooser(); file.setMultiSelectionEnabled(true);The following is an example to enable multiple selections in a JFileChooser Dialog −Examplepackage my; import javax.swing.JFileChooser; public class SwingDemo {    public static void main(String[] args) {       JFileChooser file = new JFileChooser();       file.setMultiSelectionEnabled(true);       file.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);       file.setFileHidingEnabled(false);       if (file.showOpenDialog(null) == JFileChooser.APPROVE_OPTION) {          java.io.File f = file.getSelectedFile();          System.err.println(f.getPath());       }    } }Output