T07: JavaScript Intro

JavaScript is the programming language of the web. If HTML is the structure and CSS is the style, JavaScript is the behavior. It makes pages interactive - responding to clicks, processing data, and updating content dynamically. Think of it as teaching your web page to think.

Console and Variables

The browser console is your playground. Use console.log() to print values and debug. Variables store data for later use.

// Variables
let name = "Alice";
const age = 25;
let isStudent = true;

console.log("Hello, " + name);
console.log("Age:", age);

Data Types

JavaScript has several core types: strings for text, numbers for math, booleans for true/false, null for intentional emptiness, and undefined for unset values.

Functions

Functions are reusable blocks of code. Define once, call many times.

function greet(name) {
    return "Hello, " + name + "!";
}

const add = (a, b) => a + b;

console.log(greet("Bob"));
console.log(add(3, 4));