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In this article, we will learn to center-align the items of a JComboBox in Java. The default rendering of a JComboBox uses a JLabel for each item. JLabel's default alignment is left-justified, hence the misalignment. JComboBox A JComboBox is a subclass of the JComponent class, and it is a combination of a text field and a drop-down list from which the user can choose a value. A JComboBox can generate an ActionListener, ChangeListener, and an ItemListener when the user actions with a combo box. Center-Align the Items of a JComboBox By default, items in the JCombobox are left-aligned. We ... Read More
In this article, we will learn to display the line numbers inside a JTextArea in Java. When using text editors or code viewers in Java Swing applications, the showing of line numbers can greatly improve the user experience. What is a JTextArea? A JTextArea is a subclass of JTextComponent and it is a multi-line text component to display the text or allow the user to enter a text. A JTextArea can generate a CaretListener interface, which can listen to caret update events. Syntax The following is the syntax for JTextArea initialization: JTextArea textArea = new JTextArea(); By default, JTextArea does ... Read More
In this article, we will learn to draw a rounded rectangle using the Graphics object in Java. Drawing shapes is a basic feature of Java 2D graphics programming. Though the Graphics class offers methods for drawing common rectangles, drawing rounded rectangles involves some special techniques. Graphics Class In Java, the drawing takes place via a Graphics object, which is an instance of the java.awt.Graphics class. Each Graphics object has its own coordinate system, and all the methods of Graphics, including those for drawing Strings, lines, rectangles, circles, polygons, etc. We can get access to the Graphics object through the paint(Graphics ... Read More
In Python, when working with files and directories, we may often need to access the parent directory of a given path, especially when going through a file system or managing relative paths in a project. In this article, we are going to explore the different methods available in Python to get the parent directory of the current or any specific path. Using os Module One of the commonly used methods to interact with the file system in Python is using the os module. This module provides various utilities to work with file paths and directories. To get the parent directory, ... Read More
A directory is simply defined as a collection of subdirectories and single files or either one of them. These subdirectories are separated using a "/" operator in a directory hierarchy. A directory hierarchy is constructed by organizing all the files and subdirectories within a main directory and also known as the "root" directory. Calculating the total size of a directory, i.e., all its files and subdirectories which is a common task in Python, especially when dealing with disk usage monitoring, backup management, or cleaning up storage. Python provides multiple ways to accomplish this efficiently using built-in modules such as os ... Read More
In some applications, we have to find the files on our computer programmatically to make use of out time. Python provides several powerful libraries to search and locate files by making this task straightforward and efficient. In this article, we are going to see the different methods to find a file in our system using Python. Using the os Module The os module has a method os.walk(), which is used to search for a file in the directories and their subdirectories. This method returns the file paths in a directory which allows the user to search for a specific file. ... Read More
Given are the two integer variables, a and b. To calculate the sum without using any arithmetic operators such as + or -. We can achieve this by using bitwise operations, which allow us to calculate the sum. Here, we have some approaches in C and C++ to solve this problem as follows: Sum of Two Integers Using Bitwise XOR Sum of Two Integers Using Vector Sum of Two Integers Using malloc() and free() Sum of Two Integers Using Bitwise XOR (^) To perform the sum ... Read More
In Python, the __init__.py is a special file in python packages. It is used to indicate that how a directory should be treated. When Python encounters a directory during an import, first it looks for the __init__.py file to determine how to initialize the package and what code should be executed during the import. In python 3.3 version, the __init__.py was introduced with the feature of creating a package with the namespace. Let's understand the purpose of the __init__.py file - It makes the directory a Python package so the interpreter can find the module ... Read More
No, there isn't a direct equivalent to PHP's autoloader in Python and you don't need one also. To be specific, PHP needs autoloaders for the following reasons - For each web request to start a fresh PHP process. To load all the code from scratch for every request. For optimization by loading classes only when required . To avoid loading unnecessary files which improves performance. In contrast, Python doesn't require autoloaders as files are not reread every time, and if you import ... Read More
In the 0-1 knapsack problem, a set of items is given, each with a weight and a value. We need to determine the number of each item to include in a collection so that the total weight is less than or equal to the given limit and the total value is as large as possible. In this article, we will discuss how to solve the 0-1 knapsack problem using dynamic programming. Dynamic Programming is a technique where we solve problems by breaking them into smaller sub-problems. If a subproblem is solved multiple times, DP stores the results so that we ... Read More