Php Docs

PHP Expert (8.5)

Official Documentation: https://www.php.net/manual/en/

Quick Reference

| Topic | File | |-------|------| | Installation (Linux, macOS, Windows, Docker), php.ini config, web server setup, SAPI types | getting-started.md | | PHP tags, escaping HTML, instruction separation, comments | basics-syntax.md | | Types (null, bool, int, float, string, array, object, callable, iterable, mixed, void, never, resource), type declarations, type juggling | types.md | | Variables, scope, predefined variables, variable variables, external sources | variables.md | | Constants, define(), const, magic constants, predefined constants | constants.md | | Operators (arithmetic, assignment, bitwise, comparison, error control, execution, logical, string, array, type, functional), precedence | operators.md | | Control structures (if, else, elseif, while, do-while, for, foreach, switch, match, declare, return, require, include, goto) | control-structures.md | | Functions, parameters, arguments, returning values, anonymous, arrow, first-class callable | functions.md | | Classes, objects, properties, property hooks, constants, autoloading, constructors, visibility, inheritance, static, abstract, interfaces, traits, anonymous classes, overloading, magic methods, final, cloning, late static bindings, serialization, covariance/contravariance, lazy objects | classes-objects.md | | Namespaces, sub-namespaces, importing/aliasing, global space, name resolution | namespaces.md | | Enumerations (basic, backed, methods, static methods, constants, traits, listing, serialization) | enums.md | | Errors, error levels, error handling, error reporting | errors.md | | Exceptions, try/catch/finally, extending exceptions, multiple catch types, global handler | exceptions.md | | Generators, yield, yield from, Generator class, comparison with Iterator | generators.md | | Fibers, Fiber class, suspend/resume/throw, full-stack interruptible functions | fibers.md | | Attributes, syntax, declaring attribute classes, reading with Reflection | attributes.md | | References, reference counting, passing by reference, returning references | references.md | | Predefined variables ($SERVER, $GET, $POST, $SESSION, $ENV, $GLOBALS), predefined exceptions, predefined interfaces/classes, predefined attributes | predefined.md | | Security (sessions, filesystem, database, SQL injection, error reporting, user data, hiding PHP, keeping current) | security.md | | Features (HTTP auth, cookies, sessions, file uploads, remote files, connection handling, persistent DB connections, CLI, garbage collection, DTrace) | features.md | | Standard library: strings, arrays, arrays sorting, function handling, output control, error handling | stdlib-core.md | | Standard library: date/time (DateTime, DateTimeImmutable, DateTimeZone, DateInterval, DatePeriod), calendar, HRTime | stdlib-date.md | | Standard library: math, BCMath, GMP, statistics, RoundingMode enum | stdlib-math.md | | Standard library: hash, OpenSSL, password hashing, sodium, Rnp, Xpass | stdlib-crypto.md | | Standard library: JSON, SimdJSON, cURL, DOM, SimpleXML, XMLReader, XMLWriter, XSL, XML-RPC | stdlib-xml-json.md | | Standard library: PDO, MySQL (mysqli), PostgreSQL, SQLite3, MongoDB, OCI8, ODBC, DBA, SQLSRV | stdlib-database.md | | Standard library: SPL (datastructures, iterators, exceptions, functions), reflection, fileinfo, filesystem, directories | stdlib-spl-io.md | | Standard library: compression (Phar, Zip, Zlib, Bzip2, Rar, LZF), intl, iconv, mbstring, gettext, GD, ImageMagick, Exif | stdlib-extended.md | | Standard library: PCNTL, POSIX, program execution, FFI, OPcache, session, filter, ctype, FTP, IMAP, mail, SOAP, OAuth, readline, APCu | stdlib-services.md | | Standard library: PCRE regex (pregmatch, pregreplace, pregsplit, preggrep), URL functions (parseurl, httpbuildquery, urlencode), stream functions and contexts, network functions (DNS, IP, headers), variable handling (vardump, serialize, debugbacktrace), PHP info functions | stdlib-regex-net.md | | Standard library: server-specific (Apache, LiteSpeed, FPM), Solr, FDF, GnuPG, wkhtmltox, PS, XLSWriter, Radius, GeoIP, FANN, Igbinary, Lua, CommonMark, Event, Yar, Eio, Ev, Expect, Enchant, Gender, Quickhash, dBase, Firebird, CUBRID, IBM DB2, Componere | stdlib-misc.md | | Composer, PIE, PECL, autoloading, dependency management, packaging | composer.md | | PHP 8.5 new features, 8.4/8.3/8.2/8.1/8.0 migration, deprecated features, backward incompatible changes | whats-new.md |

Core Philosophy

PHP is a widely-used, dynamically typed, general-purpose scripting language especially suited for web development. Key principles:

1. Server-Side Scripting — PHP code is executed on the server, generating HTML sent to the client
2. Dynamic Typing — types are determined at runtime, with type juggling and optional type declarations
3. Embedded — PHP can be embedded directly into HTML using `` tags
4. Multi-Paradigm — procedural, object-oriented, and functional styles all supported
5. Cross-Platform — runs on all major operating systems (Linux, macOS, Windows)
6. Rich Extension System — hundreds of built-in extensions for databases, crypto, XML, images, networking
7. Composer — modern dependency manager and package ecosystem
8. JIT Compiler — since PHP 8.0, a JIT compiler is available for improved performance

Hello World

` `=` `` | Comparison |
| `&&` `\|\|` `!` `and` `or` `xor` | Logical |
| `&` `\|` `^` `~` `>` | Bitwise |
| `.` | String concatenation |
| `??` `?:` | Null coalescing, ternary |
| `instanceof` | Type check |
| `++` `--` | Increment/decrement |

## Control Flow Quick Reference

```php
// if/elseif/else
if ($x > 0) {
    echo "positive";
} elseif ($x = 0 ? "ok" : "error";

// Null coalescing
$name = $_GET['name'] ?? 'default';

// match (PHP 8.0+)
$result = match($status) {
    200, 300 => 'success',
    400 => 'not found',
    500 => 'server error',
    default => 'unknown',
};

// foreach
foreach ($items as $key => $value) {
    echo "$key: $value\n";
}

// for
for ($i = 0; $i  $x * $x;

// First-class callable syntax (PHP 8.1+)
$callable = strlen(...);
$callable = Closure::fromCallable('strlen');

// Anonymous function / Closure
$multiply = function (int $a, int $b): int {
    return $a * $b;
};

Classes Quick Reference

// Basic class
class Dog {
    public function __construct(
        public readonly string $name,  // constructor property promotion (PHP 8.0+)
    ) {}

    public function bark(): string {
        return "{$this->name} says woof!";
    }
}

// Enum (PHP 8.1+)
enum Status: string {
    case Active = 'active';
    case Inactive = 'inactive';

    public function label(): string {
        return ucfirst($this->value);
    }
}

// Interface + Trait
interface Repository {
    public function find(int $id): ?object;
}

trait Timestampable {
    public ?DateTimeImmutable $createdAt = null;
    public ?DateTimeImmutable $updatedAt = null;
}

class User implements Repository {
    use Timestampable;

    public function __construct(
        public readonly int $id,
        public readonly string $email,
    ) {}

    public function find(int $id): ?object {
        // implementation
        return null;
    }
}

// Property hooks (PHP 8.4+)
class Account {
    private string $name = '';

    public string $displayName {
        get => $this->name ?: 'Anonymous';
        set => $this->name = trim($value);
    }
}

Installation & Setup

# Check version
php --version

# Built-in development server
php -S localhost:8000

# Run a script
php script.php

# Built-in REPL
php -a

# Composer (package manager)
composer init
composer install
composer require vendor/package
composer update

# Create project from package
composer create-project laravel/laravel myapp

Project Creation

# Simple project
mkdir myproject && cd myproject
composer init --name="acme/myproject" --type="library" --license="MIT"

# With autoloading (PSR-4)
# composer.json:
# {
#   "autoload": {
#     "psr-4": { "Acme\\": "src/" }
#   }
# }
composer dump-autoload

# Laravel project
composer create-project laravel/laravel myapp
cd myapp
php artisan serve

# Symfony project
composer create-project symfony/skeleton myapp
cd myapp
php -S localhost:8000 -t public

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: pledgeandgrow
• Source: pledgeandgrow/pledge-skills
• License: MIT

Install and usage instructions live in the source repository linked above.