Hello World Program in Java and JavaScript

Program 1: Hello World in Java

A simple Java program that prints “Hello, World!” to the console. This program serves as an introduction to Java programming and demonstrates the basic structure of a Java application.

Algorithm

Step 1: Start
Step 2: Define a public class named HelloWorld.

Step 3: Within the class, define the main method with the signature public 
        static void main(String[] args).

Step 4: Inside the main method, use System.out.println to print the string 
        "Hello, World!" to the console.

Step 5: Exit

Program in Java

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
    }
}

Step-by-Step Explanation:

Class Declaration:

public class HelloWorld {

• public: An access modifier that means the class is accessible by any other class.
• class: This keyword is used to declare a class.
• HelloWorld: The name of the class. It must match the filename (HelloWorld.java).

Main Method Declaration:

public static void main(String[] args) {

• public: The method is accessible from outside the class.

• static: This means that the method belongs to the class, not instances of the class. It can be called without creating an object of the class.

• void: The method does not return any value.

• main: The name of the method. It is the entry point for any Java program.

• String[ ] args: The parameter args is an array of String objects, which allows command-line arguments to be passed to the program.

Print Statement:

System.out.println("Hello, World!");

• System: A built-in class in the java.lang package.

• out: A static member of the System class, which is an instance of PrintStream.

• println: A method of PrintStream that prints the argument passed to it, followed by a new line. In this case, it prints “Hello, World!”.

Summary:

The HelloWorld program is a simple Java application that consists of a single class, HelloWorld. Within this class, there is a main method, which is the entry point of the program.

When the program runs, it executes the main method, which contains a single statement that prints “Hello, World!” to the console. This basic program demonstrates the structure of a Java application and how to output text to the console.

Program 2: Hello World in JavaScript

A simple JavaScript program that prints “Hello, World!” to the web page or console. This program introduces basic JavaScript syntax and the use of console.log.

Algorithm

Step 1: Start
Step 2: Use the console.log function to print the string "Hello, World!" to 
        the console.
Step 3: Exit

Program in Java

// Printing Hello, World! to the console
console.log("Hello, World!");

Explanation:

• console: This is an object provided by the JavaScript runtime (such as browsers and Node.js) that provides access to the browser’s debugging console.

• log: This is a method of the console object that outputs a message to the console.

• “Hello, World!”: This is a string literal, which is the message that will be printed to the console.;: This semicolon denotes the end of the statement. In JavaScript, semicolons are used to terminate statements, though they are optional in many cases.

Summary:

The provided JavaScript code is a simple script that prints “Hello, World!” to the console. It consists of a single-line comment that describes the purpose of the code, followed by a console.log statement that outputs the string “Hello, World!” to the console. This example illustrates the basic syntax of JavaScript for logging messages and using comments.