Introduction to PHP Programming

What is PHP?

• Hypertext Preprocessor (PHP) is a server-side scripting language
• It's general-purpose, globally used, and open-source
• Used for building dynamic websites
• Created by Rasmus Lerdorf in 1993, released in 1995
• Originally for personal home pages, now for more complex web applications

Importance of PHP

• Reliable web development program
• Used to create dynamic websites
• Easy for programmers to manipulate formats, techniques, and features
• Free and open-source
• Cross-platform compatible
• Efficient for development
• Secure
• Flexible
• Easy integration

PHP Requirements

• Web browser
• PHP engine (version PHP5 supported)
• Database server (MySQL commonly used)

PHP Comments

• Lines not executed as part of the program
• Used for notes by developers
• Common forms: //, #, /* */

PHP Variables

• Symbols representing values
• Starting with a dollar sign ($) followed by a name
• Case sensitive (e.g., $age and $AGE are different)

PHP Constants

• Identifiers for fixed values
• Cannot be changed during the script's execution
• Named using uppercase letters or underscores
• Variables differ - must start with a $

PHP Data Types

• (Not explicitly named in the provided text, but implied by operations described)

PHP Operators

• Arithmetic: Used for mathematical operations (+, -, *, /, %, etc.)
• Comparison: Used for comparing values (==, !=, >, <, >=, <=, ===, !==)
• Logical: Used to combine conditions (AND, OR, XOR, NOT)
• String: Used for manipulating text
  • Concatenation (+ or .), assignment concatenation (.=).

PHP Superglobal Variables

• Special variables accessible throughout the script
• Global scope, useful instead of 'global' keyword
• $GLOBALS array, containing all global variables

Loops (FOR, WHILE, DO...WHILE, FOREACH)

• Repeating code blocks based on conditions
• FOR : iterates a specific number of times
• WHILE : loops as long as a condition is true
• DO...WHILE : executes a block at least once, then loops while condition is true
• FOREACH: loops through each element in an array

Conditional Statements (IF, ELSE, ELSE IF)

• Execute different blocks of code based on conditions
• IF, ELSE IF, ELSE: provide choices for different scenarios

PHP Functions

• Blocks of reusable code performing specific tasks
• Names are similar to variables (first letter is a letter or underscore)
• Functions to create, modify, and present data to users

PHP Form Handling

• $_POST and $_GET collect data from forms
• GET : data displayed in the URL, limited size
• POST : data sent in the request body, not displayed, no size limit

Include & Require

• include : includes a file, generates warning if file not found
• require : includes a file, generates an error if file not found; stops execution

PHP Strings

• Sequences of characters
• Enclosed in single or double quotes

This quiz covers the essentials of PHP, a widely used server-side scripting language. Participants will explore its history, functionality, and key features, including the use of variables and comments in PHP code. Test your knowledge on how PHP powers dynamic websites and its integration capabilities.