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Java

Java

Exception Handling

Exception Handling

Exception handling in Java lets you manage errors and prevent program crashes.

Example of try-catch block:

try {

int result = 10 / 0;
} catch (ArithmeticException e) {

System.out.println(“Error: Division by zero!”);

}

Object-Oriented Programming Basics

Object-Oriented Programming Basics

Classes and Objects
Java is object-oriented, so you use classes as blueprints to create objects.

Encapsulation, Inheritance, and Polymorphism
Java’s OOP principles enhance modularity and reusability in code.

Functions and Methods

Functions and Methods

Functions help you organize code into reusable blocks. Java supports method overloading, where multiple methods have the same name but different parameters.

Example:

<span class="hljs-keyword">public</span> <span class="hljs-type">int</span> <span class="hljs-title function_">add</span><span class="hljs-params">(<span class="hljs-type">int</span> a, <span class="hljs-type">int</span> b)</span> {
<span class="hljs-keyword">return</span> a + b;
}
<span class="hljs-keyword">public</span> <span class="hljs-type">double</span> <span class="hljs-title function_">add</span><span class="hljs-params">(<span class="hljs-type">double</span> a, <span class="hljs-type">double</span> b)</span> {
<span class="hljs-keyword">return</span> a + b;
}

Arrays and Collections

Arrays and Collections

Introduction to Arrays
Arrays store multiple values in a single variable, with all elements sharing the same data type.

Overview of Collections
Collections such as ArrayList and HashMap provide flexible storage options for dynamic data handling.

Control Flow Statements

Control Flow Statements

Conditional Statements
Java supports if, else if, else, and switch statements to manage the flow of a program.

Looping Statements
Loops like for, while, and do-while allow repetitive tasks until a condition is met. For example:

<span class="hljs-keyword">for</span> (<span class="hljs-type">int</span> <span class="hljs-variable">i</span> <span class="hljs-operator">=</span> <span class="hljs-number">0</span>; i < <span class="hljs-number">5</span>; i++) {
System.out.println(<span class="hljs-string">"Iteration: "</span> + i);
}

Operators in Java

Operators in Java

Java has several operators that perform different operations:

  • Arithmetic Operators: Used for mathematical calculations.
  • Relational Operators: Compare two values.
  • Logical Operators: Used to combine boolean expressions.
  • Assignment Operators: Assign values to variables.

For example:

<span class="hljs-type">int</span> <span class="hljs-variable">a</span> <span class="hljs-operator">=</span> <span class="hljs-number">10</span>;
<span class="hljs-type">int</span> <span class="hljs-variable">b</span> <span class="hljs-operator">=</span> <span class="hljs-number">20</span>;
<span class="hljs-type">int</span> <span class="hljs-variable">sum</span> <span class="hljs-operator">=</span> a + b; <span class="hljs-comment">// Arithmetic operator</span>

Variables and Data Types

Variables and Data Types

Introduction to Variables
Variables store data values, and in Java, they must be declared with a specific data type.

Primitive Data Types in Java
Examples include int, double, char, and boolean. Each type serves a different purpose and uses different memory.

Non-Primitive Data Types
Arrays, strings, and classes are examples of non-primitive data types, which hold references rather than actual data.

Basic Syntax and Structure

Basic Syntax and Structure

Understanding Java Syntax
Java syntax is structured and follows strict rules. Every Java program must have a class and a main method, which serves as the entry point.

Structure of a Java Program
A Java program typically includes packages, classes, and methods.

Comments and Readability
Java supports both single-line (//) and multi-line comments (/*...*/), making code more readable and manageable.

Getting Started with Java

Getting Started with Java

Introduction to Java Development Environment
Java development requires setting up the Java Development Kit (JDK) and Java Runtime Environment (JRE). The JDK provides tools for writing and compiling Java code, while the JRE allows you to run Java applications.

Setting Up Java (Installation of JDK and JRE)
To install Java, visit Oracle’s official website, download the JDK, and follow the setup instructions for your OS.

Writing Your First Java Program
Create a file named HelloWorld.java with the following code:

<span class="hljs-keyword">public</span> <span class="hljs-keyword">class</span> <span class="hljs-title class_">HelloWorld</span> {
<span class="hljs-keyword">public</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> <span class="hljs-title function_">main</span><span class="hljs-params">(String[] args)</span> {
System.out.println(<span class="hljs-string">"Hello, World!"</span>);
}
}

Run the program using the command java HelloWorld to see the output “Hello, World!” displayed on your screen.

Java Tutorials for Beginners

Java Tutorials for Beginners

Introduction

Java is a widely-used programming language that has become an essential tool for developers around the world. Known for its simplicity, robustness, and versatility, Java is perfect for beginners who want to step into the programming world. Whether you’re aiming to build mobile applications, web services, or complex systems, Java provides a solid foundation. This book, “Java Tutorials for Beginners,” will walk you through everything you need to know about Java, from basics to advanced concepts, with easy-to-understand explanations and examples.