Study Notes: PHP Basics and Advanced Topics

1. Introduction to PHP

• Definition: PHP (PHP Hypertext Preprocessor) is a server-side scripting language used for creating dynamic and interactive web pages.
• Key Features:
  • Free, open-source, and efficient.
  • Compatible with various platforms (Windows, Linux, Unix, Mac OS X).
  • Supports a wide range of databases.
  • Executes on the server, returning plain HTML to the browser.
  • File extension: .php.

2. What Can PHP Do?

• Generate dynamic page content.
• Perform file operations (create, open, read, write, delete, close).
• Collect form data.
• Send and receive cookies.
• Interact with databases (add, delete, modify data).
• Restrict user access to specific pages.
• Encrypt data.
• Output various formats: HTML, images, PDFs, Flash movies, XML, etc.

3. Basic PHP Syntax

• PHP scripts are enclosed within <?php ... ?>.

• Example:

  <?php
  echo "Hello World!";
  ?>
  
  

• Can be placed anywhere in an HTML document.