PHPProgramming Study Notes

Abstract Classes and Polymorphism

Abstract classes define a partial implementation and a contract that subclasses must complete, enabling polymorphic code that treats different concrete types u…

Array Functions

Survey PHP's extensive standard-library array functions for transforming, filtering, searching, and reducing arrays without manual loops.

Attributes in PHP

Attributes are PHP's native, structured metadata syntax (introduced in PHP 8.0) that let you annotate classes, methods, and properties with machine-readable da…

Autoloading with Composer

See how Composer's PSR-4 autoloader eliminates manual require statements by mapping namespaces to directories and generating an efficient class-loading map.

Classes and Objects

Explore PHP's object-oriented foundations: declaring classes, constructing objects, typed properties, visibility, and constructor promotion.

Common PHP Pitfalls

A field guide to PHP's most persistent gotchas — loose comparison surprises, array reference bugs, and mutable state traps — and how to avoid them.

Composer and Package Management

Learn how Composer manages PHP project dependencies, autoloading, versioning, and the composer.json/composer.lock files that define a project's package graph.

Conditionals in PHP

Covers if/elseif/else, the ternary and null-coalescing shortcuts, switch statements, and alternative control-structure syntax used in templates.

Data Types in PHP

A tour of PHP's scalar, compound, and special types, plus how PHP's dynamic typing and type juggling behave in practice.

Enums in PHP

PHP 8.1 enums provide a first-class way to define a fixed set of named values, with optional scalar backing, methods, interfaces, and constants attached.

Exceptions and Error Handling

Learn how PHP represents runtime failures as throwable objects, how try/catch/finally blocks control the flow around them, and how to design a clean exception…

File Uploads in PHP

Learn how PHP handles multipart form uploads through the $_FILES superglobal, including validation, error codes, and safely moving uploaded files on disk.

Form Handling and Validation

Learn a reliable pattern for processing submitted HTML forms in PHP: reading input safely, validating and sanitizing each field, and reporting errors back to t…

Functions in PHP

Learn how PHP functions are declared, typed, and invoked, including default parameters, variadics, references, and closures for reusable logic.

Indexed and Associative Arrays

Understand PHP's single array type used for both ordered lists and key-value maps, including creation, iteration, and common manipulation patterns.

Inheritance and Interfaces

Understand how PHP classes extend one another via single inheritance and implement contracts via interfaces, including method overriding rules.

Loops in PHP

Explains PHP's for, while, do-while, and foreach loops, along with break, continue, and reference-based iteration pitfalls.

Magic Methods

Magic methods are special, double-underscore-prefixed hooks PHP invokes automatically for events like object construction, property access, and string conversi…

Match Expressions

Introduces PHP 8's match expression, its strict comparison semantics, and why it is often a safer, more concise replacement for switch.

Named Arguments and the Nullsafe Operator

Named arguments let callers pass function parameters by name in any order, and the nullsafe operator short-circuits chained property/method access safely when…

Namespaces in PHP

Understand how PHP namespaces prevent naming collisions between classes, functions, and constants, and how import statements and resolution rules connect them…

Operators and Expressions

Explains PHP's arithmetic, comparison, logical, assignment, and null-coalescing operators, along with operator precedence and expression evaluation order.

PDO Database Basics

An introduction to PHP Data Objects (PDO), the consistent, driver-agnostic interface PHP provides for connecting to and querying relational databases.

PHP Interview Questions

A curated set of PHP interview questions spanning language fundamentals, OOP, and modern PHP 8.x features, with concise correct answers.