PHP

A popular specific-purpose scripting language that is especially suited to web development.

When to Use

• Server-side web development
• WordPress / CMS development
• Content-heavy sites
• Rapid prototyping

Quick Start

<?php
$name = "World";
echo "Hello, $name!";

$colors = ["red", "green", "blue"];
foreach ($colors as $color) {
    echo $color . "<br>";
}
?>

Core Concepts

Arrays

PHP arrays are versatile (serve as lists, maps, stacks, etc.).

$user = [
    "id" => 1,
    "name" => "Foo"
];

Superglobals

Built-in variables available in all scopes ($_GET, $_POST, $_SESSION).

OOP

PHP 8+ has robust object-oriented features including properties, attributes, and match expressions.

Best Practices

Do:

• Use Composer for dependency management
• Type hint function arguments and return types
• Use PDO for database access (prepared statements)
• Follow PSR standards (PSR-12)

Don't:

• Use mysql_ functions (deprecated/removed)
• Trust user input (sanitize/validate)
• leave display_errors on in production

References

• PHP.net
• PHP The Right Way