Difficulty: Intermediate | Prerequisites: Java Fundamentals, OOP Concepts, Methods.

Big Picture

This unit moves beyond pure Java into two related areas: building web pages with HTML, CSS, and JavaScript, and building desktop applications with Java Swing. It also covers the software development lifecycle (SDLC) and testing strategies. These topics show you how programming concepts translate into things users see and interact with. If you are behind, make sure you understand methods, event-driven thinking (a user does something, the program responds), and basic OOP before starting here. The web portion is largely standalone, but Swing relies on inheritance and interfaces from the OOP unit.

TL;DR

HTML provides structure, CSS provides styling, and JavaScript provides interactivity for web pages. Java Swing uses components like JButton and JFrame with layout managers and event listeners to build desktop GUIs. The SDLC covers the stages from design through testing, and testing strategies include unit testing, regression testing, and edge-case testing.

Key Terms

HTML (HyperText Markup Language)

The standard language for structuring web page content. HTML uses tags (e.g.,

,

, ) to define elements and attributes to configure them. Think of HTML as the skeleton of a web page.

Tag

An HTML element marker. Most tags come in pairs: an opening tag (

) and a closing tag (

). Some are self-closing ().

Attribute

A name-value pair inside an opening tag that configures the element. Examples: src for images, href for links, alt for alternative text.

CSS (Cascading Style Sheets)

A language for controlling the visual appearance of HTML elements: colours, fonts, spacing, layout. CSS can be written inline, in a