UNIT 2 CLIENT SIDE PROGRAMMING

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2.1 JAVA SCRIPT: INTRODUCTION TO JAVA SCRIPT

JavaScript is a versatile, dynamically-typed programming language used to create interactive and dynamic web experiences. It is one of the three core technologies of the World Wide Web, alongside HTML (structure) and CSS (style).

Key Concepts
  • Scripting Language: JavaScript code (scripts) can be embedded directly into HTML pages and executed automatically by the browser. It is an interpreted language, meaning it runs line by line without needing special compilation beforehand.
  • Client-Side and Server-Side: Originally a client-side language (running in the user's browser), JavaScript can now also be used on the server-side with runtime environments like Node.js. This allows developers to build full-stack applications using a single language.
  • Dynamically Typed: Variable data types are determined at runtime, offering flexibility but requiring careful handling to avoid errors.
  • Event-Driven: It can respond to user actions like clicks, key presses, and form inputs in real-time, which is essential for interactivity.
  • Integration with HTML/CSS: JavaScript has full access to the Document Object Model (DOM), allowing it to dynamically change HTML content, attributes, and CSS styles on a page.
Primary Uses

  • Making Web Pages Interactive: The most common use, adding dynamic behavior like animations, pop-ups, form validation, and interactive maps.
  • Web and Mobile Applications: With frameworks like React, Angular, and Vue, developers can build complex web applications. Frameworks like React Native are used for creating native mobile applications.
  • Building Web Servers and Backend Logic: Node.js enables JavaScript to handle server-side tasks, interact with databases, and manage files.
  • Game Development and IoT: It can be used for creating browser-based games and applications for Internet of Things devices.

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