PHP BEGINNER

PHP Fundamentals

Modern PHP 8+ syntax, features, and best practices for building robust web applications

12 min read

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Setup & Basics

Getting started with PHP

Installation & Setup

Installing PHP and setting up development environment

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🚀 PHP 8.3 brings major performance improvements

📦 Composer is the standard dependency manager

🔧 Built-in server perfect for development

⚡ PHP-FPM recommended for production

PHP Syntax Basics

Basic PHP syntax and structure

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💡 PHP files start with <?php tag

📌 Variables always start with $ sign

⚡ Use require for critical files, include for optional

🔥 Constants are globally accessible and immutable

Data Types

PHP data types and type declarations

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💡 PHP is dynamically typed but supports type hints

⚡ Use strict_types=1 for type safety

📌 Union types allow multiple possible types

🔥 Never type indicates function never returns

Control Structures

Conditionals, loops, and control flow

Conditionals

If statements, switch, and match expressions

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💡 Match is stricter than switch (no type coercion)

⚡ Null coalescing (??) simplifies default values

📌 Match returns values, switch executes code

🔥 Alternative syntax cleaner for templates

Loops

Different types of loops in PHP

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💡 Use foreach for arrays, for when you need index

⚡ Reference (&) in foreach allows modification

📌 Always unset references after foreach

🔥 Break/continue can specify nesting level

Functions & Closures

Functions, closures, and arrow functions

Functions

Function declaration and parameters

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💡 Named arguments improve readability

⚡ Variadic functions accept unlimited arguments

📌 Pass by reference with & to modify variables

🔥 Type hints catch errors early

Closures & Arrow Functions

Anonymous functions and arrow functions

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💡 Arrow functions auto-capture parent scope

⚡ Use & to modify external variables in closures

📌 Arrow functions always return (no void)

🔥 First-class callables simplify syntax in PHP 8.1+

Arrays

Array manipulation and operations

Array Basics

Creating and accessing arrays

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💡 Use [] syntax for arrays (modern PHP)

⚡ Spread operator (...) unpacks arrays

📌 array_key_exists vs isset: isset returns false for null

🔥 Destructuring makes code cleaner

Array Functions

Built-in array manipulation functions

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💡 array_map transforms, array_filter selects, array_reduce aggregates

⚡ Spaceship operator (<=>) simplifies comparisons

📌 array_merge re-indexes, + operator preserves keys

🔥 array_column great for extracting from multi-dimensional arrays

Object-Oriented PHP

Classes, objects, and OOP concepts

Classes & Objects

Basic class definition and object creation

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💡 Constructor property promotion reduces boilerplate

⚡ Readonly properties ensure immutability

📌 Use visibility modifiers for encapsulation

🔥 Static properties/methods shared across all instances

Inheritance & Interfaces

Extending classes and implementing interfaces

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💡 Interfaces define contracts, abstract classes provide partial implementation

⚡ Traits enable horizontal code reuse

📌 Use final to prevent inheritance

🔥 Late static binding with static:: for proper inheritance

PHP 8 Features

Modern PHP 8+ features and improvements

PHP 8.0 Features

Major features introduced in PHP 8.0

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💡 Match expressions are safer than switch (no fall-through)

⚡ Nullsafe operator prevents null reference errors

📌 Constructor promotion reduces boilerplate significantly

🔥 JIT compilation dramatically improves CPU-intensive tasks

PHP 8.1+ Features

Features from PHP 8.1, 8.2, and 8.3

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💡 Enums provide type-safe constants with methods

⚡ Readonly properties/classes ensure immutability

📌 First-class callables simplify functional programming

🔥 Fibers enable async programming without callbacks

Error Handling

Exception handling and error management

Exceptions

Working with exceptions and try-catch blocks

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💡 Use specific exception types for different errors

⚡ Finally block always executes for cleanup

📌 Chain exceptions to preserve error context

🔥 Throwable catches both Exception and Error types

Database & PDO

Database connections and operations with PDO

PDO Basics

Connecting to databases and executing queries

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💡 Always use prepared statements to prevent SQL injection

⚡ Use transactions for related operations

📌 PDO supports multiple databases with same interface

🔥 Set PDO::ERRMODE_EXCEPTION for better error handling

String Manipulation

Working with strings in PHP

String Operations

Common string manipulation functions

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💡 Use mb_* functions for multibyte (UTF-8) strings

⚡ str_contains/starts_with/ends_with are PHP 8.0+ additions

📌 Always use htmlspecialchars() for user input in HTML

🔥 Heredoc parses variables, Nowdoc does not

File Handling

Reading and writing files

File Operations

Working with files and directories

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💡 Use file_get_contents for simple reads, handles for large files

⚡ Always check file_exists() before operations

📌 Use LOCK_EX flag to prevent race conditions

🔥 Set proper permissions (0755 for dirs, 0644 for files)

Web Features

Sessions, cookies, and HTTP handling

Sessions & Cookies

Managing user sessions and cookies

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💡 session_start() must be called before any output

⚡ Use secure, httponly, and samesite for cookie security

📌 Always exit() after header redirects

🔥 Regenerate session ID after login to prevent fixation

JSON & APIs

Working with JSON and building APIs

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💡 Always validate JSON with json_last_error()

⚡ Use php://input for raw POST data

📌 Set proper Content-Type and status codes

🔥 json_validate() in PHP 8.3+ checks without decoding

Advanced Features

Generators, regex, and namespaces

Generators & Iterators

Memory-efficient iteration with generators

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💡 Generators use yield to pause and resume execution

⚡ Perfect for processing large datasets with low memory

📌 yield from delegates to another generator

🔥 Generators maintain state between iterations

Regular Expressions

Pattern matching with regex

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💡 Use preg_quote() to escape user input in patterns

⚡ Named groups make matches more readable

📌 Add pattern modifiers: i (case), m (multiline), s (dotall)

🔥 preg_replace_callback for complex replacements

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