Java Programming Basics with Examples

📌 Array in Java (Professional & Beginner-Friendly Explanation) 🔹 What is an Array? An array in Java is an object that is used to store multiple values of the same (homogeneous) data type under a single variable name. Arrays store data using index positions. The size of an array is fixed once it is created. Array indexing starts from 0 and ends at size – 1. When an array is created in Java, an internal class is generated by the JVM. This internal class contains a final variable called length, which stores the size of the array. 🔹 Key Characteristics of Arrays Stores homogeneous data only Index-based data access Fixed size (cannot grow or shrink) Faster data access compared to collections 🔹 Syntax to Create an Array in Java 1️⃣ Using new keyword dataType[] arrayName = new dataType[size]; Example: int[] numbers = new int[5]; 2️⃣ Using Array Literal dataType[] arrayName = {value1, value2, value3}; Example: int[] numbers = {10, 20, 30, 40}; 🔹 Types of Arrays in Java 1️⃣ Primitive D...

Scanner Class. Scanner Class is present inside the java.util package. It is used for the take the input from user. Scanner Class method. nextByte();read byte data. nextShort();read short data. nextInt();read integer data. nextLong();read long data. nextFloat();read float data. nextDouble();read double data. nextBoolean();read boolean data. next();read string and character data. nextLine();read string data.

📘 File Reading in Java (Using FileReader Class) What is File Reading in Java? File Reading in Java is the process of reading data from a file stored on the system. Java provides the FileReader class (not “File Reading”) inside the java.io package to read character-based data from files. 📦 FileReader Class The FileReader class is used to read text data from a file character by character. 📌 Package java.io 🧱 Constructor of FileReader FileReader(String filePath) throws FileNotFoundException Opens a file located at the given file path. Internally creates an input stream to read data from the file. Throws FileNotFoundException if the file does not exist. 🛠️ Methods of FileReader Method.               Description int read().    Reads one character at a time and returns its ASCII (Unicode) value void close().   Closes the input stream and releases system resources 🔄 How File Reading Works (Step by Step) 1. Create a FileReader ob...