/lighthouse-labs-advanced-lecture-php

Primary LanguagePHP

Week 25 | Advanced Lecture: PHP Introduction

What is PHP?

  • Interpreted programming language
  • Developed originally in 1994 - Rasmus Lerdorf
  • Personal Home Page (Tools)
  • PHP Hypertext Preprocessor
  • Is maintained by the PHP Group
  • Is currently being updated

Why NOT use PHP - I've heard bad things...

  • Weak-typing, and not much enforced convention. This can be powerful in that you have more choice... however, things have more opportunity to go wrong.
  • World-wide adoption and popularity means more code and examples of all types... often bad ones!

Why USE PHP then?

  • 70% or more of web applications use PHP
  • 40% or more of web applications use WordPress (blogging)
  • It is free and flexible
  • Ease-of-use, pre-installed on most web servers
  • Package manager: Composer
  • PHP's leading MVC framework: Laravel

Installing PHP

Some Common Command-Line Options

  • (Execute a file) php ./path/to/your/script.php
  • (Run a test server) php -S localhost:3000
  • (Execute code in a string) php -r ""
  • (Run an interactive shell) php -a

Data-Types

  • Strings (concatenations via ., double versus single quotes)
  • Integers
  • Floats (/Doubles)
  • Boolean (true/false)
  • NULL (NULL)
  • Resource
  • Arrays (array() versus [] syntax, indexed and associative arrays)
  • Objects (json_encode and json_decode are common for data transfer)

Useful Tips

  • You can use include to run another PHP file's contents in your script
  • Use var_dump() or print_r() to get more info about a value
  • Remember + is only used for mathematics in PHP, so it will attempt to convert any values to numbers on either side
  • Global array variables exist for $_GET, $_POST, and $_SESSION, allowing for easy access and manipulation of form submissions and session-specific values

Resources