PHP Introduction

What is PHP?

  • PHP is a server-side scripting language.
  • Embed PHP in HTML for dynamic web pages.
  • Loosely typed, dynamically assigned variables.
  • Extensive library support, including frameworks.
  • Strong database integration with MySQL, PostgreSQL.
  • Open source, community-driven development.
  • Cross-platform compatibility (Windows, Linux, macOS).                                                                                                                                                                    
PHP is an amazing and popular language!
It is powerful enough to be at the core of the biggest blogging system on the web (WordPress)! 
It is deep enough to run large social networks! 
It is also easy enough to be a beginner's first server side language!


What is a PHP File?

  • PHP files can contain text, HTML, CSS, JavaScript, and PHP code
  • PHP code is executed on the server, and the result is returned to the browser as plain HTML
  • PHP files have extension ".php"

What Can PHP Do?

  • Dynamic Web Pages: Create interactive and dynamic web pages by embedding PHP code within HTML.                                                                                                                                                                                 
  • Form Handling: Process and validate user input from HTML forms, such as login forms and contact forms.                                                                                                                                                                            
  • Database Interaction: Connect to databases (e.g., MySQL, PostgreSQL) to store, retrieve, and manipulate data.                                                                                                                               
  • User Authentication: Implement user authentication and access control systems for secure web applications.                                
  • File Handling: Read from and write to files on the server, allowing for file uploads, downloads, and manipulation.                            
  • Session Management: Maintain user sessions across multiple pages for personalized and stateful web experiences.                     
  • Content Management Systems (CMS): Power popular CMS platforms like WordPress, Joomla, and Drupal.                       
  • Server-Side Scripting: Execute code on the server to perform tasks, reducing the load on the client side.                                              
  • API Development: Build and consume APIs for communication between different software applications.                     
  • Image Processing: Manipulate and process images, generate thumbnails, or create dynamic image content.                              
  • XML and JSON Handling: Parse and generate XML and JSON data for data interchange between applications.                           
  • Cryptography: Implement encryption and hashing for secure data storage and transmission.                                                  
  • Web Services: Develop and consume web services, enabling communication between different web applications.                              
  • Email Handling: Send emails through SMTP, validate email addresses, and process incoming emails.                                                 
  • Command-Line Scripting: Execute PHP scripts from the command line for various automation tasks.                    
  • RESTful Services: Create or consume RESTful services for building scalable and interoperable web applications.                
  • Session Cookies: Use cookies to store and retrieve information about users for a personalized browsing experience.                                 
  • Regular Expressions: Perform powerful text pattern matching and manipulation using regular expressions.                       
  • Error Handling: Implement error handling to manage and log errors for debugging and maintenance.                                                                       

Template Engines: Use template engines to separate HTML and PHP code for better code organization and maintainability.

With PHP you are not limited to output HTML. You can output images or PDF files. You can also output any text, such as XHTML and XML.

Why PHP?

  • Ease of Learning: PHP is relatively easy to learn for beginners, especially those with a background in programming. Its syntax is straightforward and similar to other C-based languages, making it accessible for many developers.                                                                                                                                                                                                       
  • Open Source: PHP is an open-source language, which means it's freely available for anyone to use and modify. This has contributed to a large and active community of developers, resulting in extensive documentation, resources, and support.                                                                                                                                                                                      
  • Versatility: PHP is versatile and can be embedded within HTML code. This makes it easy to integrate PHP into existing web pages or create dynamic content.                          
  • Cross-Platform Compatibility: PHP is compatible with various operating systems, including Windows, Linux, and macOS. This cross-platform compatibility makes it flexible for deployment on different server environments.                                                                                                                                                                                                                                          
  • Server-Side Scripting: PHP is designed specifically for server-side scripting. This means that code is executed on the server, and only the results are sent to the client's browser. This helps in creating dynamic web pages and handling various tasks on the server.                                                                                                                                                  
  • Large Community and Support: PHP has a large and active community of developers. This community support is crucial for problem-solving, sharing knowledge, and keeping the language up-to-date with emerging web development trends.                                                                                                                                                                                       
  • Integration Capabilities: PHP can easily integrate with various databases, such as MySQL, PostgreSQL, and others. This makes it a suitable choice for building dynamic and database-driven websites.                                                                                  
  • Frameworks: PHP has several frameworks like Laravel, Symfony, and CodeIgniter that simplify and streamline the development process. These frameworks provide reusable components and follow best practices, making it easier to develop robust and scalable applications.
    My first PHP page
echo "Hello World!";

What's new in PHP 8

  • Just-In-Time Compilation (JIT): PHP 8 introduced a JIT compiler that can improve the performance of certain applications by dynamically translating the PHP bytecode into machine code at runtime.
  • Union Types: PHP 8 introduced support for union types, allowing a variable to accept values of multiple different types.
  • Named Arguments: Named arguments allow developers to pass values to a function by specifying the parameter name, making function calls more readable and reducing the likelihood of errors.
  • Attributes: Attributes provide a way to add metadata to classes, functions, and class properties. This is a more structured way of adding information to code compared to comments or docblocks.
  • Match Expression: The match expression is an enhanced replacement for the switch statement, providing a more concise syntax and better functionality.
  • Nullsafe Operator: The nullsafe operator (?->) allows developers to make a chain of calls with the confidence that if any part of the chain returns null, the whole expression will gracefully return null instead of causing an error.
  • Weak Maps: PHP 8 introduced WeakMap, a new class that allows creating maps where keys are objects, and those objects are not prevented from being garbage-collected.
  • New Functions and Classes: PHP 8 introduced several new functions and classes, including str_contains() for checking if a string contains another string, get_debug_type() for retrieving the type of a variable, and the Stringable interface.