What is JavaScript?

JavaScript (JS) is a programming language commonly used in web development to add interactivity and dynamic behavior to websites. It's often run in web browsers, allowing for tasks such as validating forms, creating interactive maps, and updating content without needing to reload the entire page.

const message = "Hello, world!";
console.log(message);

JavaScript is widely used because it's the primary language for adding interactivity and dynamic features to websites, making web pages more engaging and responsive.

Why Java Script?

Easy to learn: JavaScript has a relatively simple and easy-to-understand syntax, which makes it a good starting point for beginners.

Accessible: JavaScript can be run directly in most web browsers without any complex setup.

In-demand skill: JavaScript is one of the most popular programming languages in the world.

Basic JavaScript Structure:

Comments: Start by familiarizing yourself with comments. These are lines of text ignored by the computer but help you understand your code. They're great for explaining what different parts of your code do. You can add comments with // for single lines or /* */ for multi-line comments.

Variables: Variables are like containers that hold data you can use in your code. You give them a name and assign a value (like a number, text, or true/false). Learn how to declare variables with let or const keywords and how to assign values with the = operator.

Data Types: The type of data your variable holds is important. In JavaScript, common data types include numbers (10), strings ("hello"), booleans (true or false), and arrays ([] for lists).

Simple Math: JavaScript can perform basic math operations like addition (+), subtraction (-), multiplication (*), and division (/). You can use these with variables and numbers.

Input and Output: Use the console.log() function to display messages and data in the browser's console, like a log of what your code is doing.

Control Flow: Use if statements to make decisions based on conditions. The if statement checks if something is true, and if it is, it runs a block of code. You can also use else for what happens if the condition isn't true.

Loops: Loops allow you to repeat a block of code multiple times. Common loops include for loops (repeat a specific number of times) and while loops (repeat as long as a condition is true).

Functions: Functions are reusable blocks of code that perform a specific task. You can define functions with the function keyword, give them a name and parameters (inputs), and write the code they execute. Functions can return values using the return keyword.

Once you're comfortable with these basics, you can explore more advanced topics like objects, DOM manipulation (interacting with web pages), and working with events (user interactions).

// Variable declaration
  const userName;
  const age;
  
  // Assign values to variables
  userName = "John";
  age = 30;
  
  // Function declaration
  function greetUser() {
      // Function body
     // console.log("Hello, " + userName + "! You are " + age + " years old.");
  }
  
  // Function call
  greetUser();

  Output - Hello, John! You are 30 years old.
 

Above you see the basic structure of the javascript to print " Hello, John! You are 30 years old."