Algorithms and Data Structures in PHP: From Basics to Advanced Techniques

This book is a comprehensive guide to algorithms and data structures, written specifically for PHP developers. Unlike abstract textbooks, all examples here are given in live PHP code, ready for use in real projects. You will learn not just to "go through algorithms," but to understand how they work "under the hood" and how to apply them to solve everyday tasks: from processing large data arrays to building complex search and recommendation systems.

Who is this book for?

• Junior and Middle PHP developers who want to move to the next level and write not just working, but fast and scalable code.
• Backend programmers preparing for technical interviews — the book covers classic problems and approaches to solving them.
• Anyone who uses PHP and wants to understand how standard functions (sorting, searching, working with collections) work and how they can be improved.

What will you learn and be able to do?

• Understand how arrays, lists, stacks, queues, hash tables, and trees work in the context of PHP.
• Master sorting algorithms (bubble, quick, merge, heap) and learn to choose the optimal option for your task.
• Learn to work with graphs and implement breadth-first and depth-first search — for building site maps, social graphs, or routing systems.
• Discover how to use dynamic programming for optimization problems (e.g., the knapsack problem or finding the longest common substring).
• Analyze real-world cases: how to speed up product catalog loading, how to process millions of records without memory overload, how to implement search autocomplete.
• Get ready-made templates and patterns that can be immediately applied in frameworks (Laravel, Symfony) and pure projects.

The book is built on the principle of "from simple to complex": first you will cover basic structures and algorithms, then move on to advanced topics — B-trees, hashing, string algorithms, and working with external data. Each chapter contains practical tasks and performance measurement examples so you can visually see the difference between "bad" and "good" code.

This is not a reference book — it is a textbook that will teach you to think algorithmically. After reading it, you will be able to independently design efficient architectures, avoid common mistakes, and feel confident in interviews at large IT companies.