Swing components In Simply, component means a widget which is a thing we can put in a GUI, a thing a user sees and interacts with. Text fields, buttons, scrollable lists, radio buttons, etc. are all examples of components. All the components are extended from javax.swing.JComponent. With the exception of JFrame, though…

JFrame A JFrame is the object that represents a window on the screen. It’s where you put all the interface things like buttons, checkboxes, text fields, etc. The JFrame looks different depending on the platform. Making a GUI is easy Steps: · Make a frame (a JFrame) JFrame frame = new JFrame(); · Make a widget…

Java sound API — JavaSound is a collection of classes and interfaces added to Java starting with version 1.3. JavaSound is split into two parts: MIDI and Sampled. MIDI stands for Musical Instrument Digital Interface and is a standard protocol for getting different kinds of electronic sound equipment to communicate. …

Methods in the Math class don’t use any instance variable values. And because the methods are “static”, you don’t need to have an instance of Math. All you need is the Math class. Java is object-oriented, but once in a while you have a special case, typically a utility method…

Stack and Heap In Java, we (programmers) care about two areas of memory. · The one where objects live (the heap) · The one where method invocations and local variables live (the stack). Methods on the top of the stack is always the currently executing method.

Abstract class An abstract class means that nobody can ever make a new instance of that class. You can still use that abstract class as a declared reference type, for the purpose of polymorphism, but you don’t have to worry about somebody making objects of that type. The compiler guarantees it. Concrete Class A…

Inheritance Inheritance is a key feature of object-oriented programming that allows the creation of a new class from an existing class. Here the new class is called a subclass and is also known as a child or derived class. …

ArrayList — What is ArrayList? The ArrayList class is a resizable array, which can be found in java. util package. Inbuilt methods of ArrayList add(Object element) => Adds the object parameter to the list. remove(int index) => Removes the object at the index parameter. remove(Object element) => Removes this object (if it’s…

Developing a class — Steps First determine what the class is supposed to do Declare the instance variables and methods Write prep code for the methods Write test code for the methods Implement the class Then test the methods. Main three things that we approach to write a class Prep code: A form of pseudocode that allows focusing on the logic rather than the…