PHP Data & APIs

advanced

What You'll Learn

Theory

PHP is widely used for building data-driven web applications. It provides excellent support for databases, JSON processing, and API development.

PHP with Databases

PHP connects to databases using PDO (PHP Data Objects) — a consistent interface for multiple database types:

$pdo = new PDO(
    "mysql:host=localhost;dbname=myapp",
    $user, $password
);
 
$stmt = $pdo->prepare(
    "SELECT * FROM users WHERE id = ?"
);
$stmt->execute([$id]);
$user = $stmt->fetch(PDO::FETCH_ASSOC);

Prepared statements prevent SQL injection by separating query logic from data.

JSON APIs

PHP natively supports JSON with json_encode() and json_decode():

header("Content-Type: application/json");
$data = ["name" => "Alice", "age" => 25];
echo json_encode($data);

Modern PHP Patterns

MVC frameworks — Laravel, Symfony separate concerns
Composer — dependency manager for PHP libraries
PSR standards — PHP-FIG coding standards (PSR-4 autoloading, PSR-7 HTTP messages)
Type declarations — PHP 7+ supports strict types for function parameters and return values
Named arguments — PHP 8+ allows passing arguments by parameter name

Simple REST API Endpoint

php

Why this matters

Modern PHP development goes far beyond simple scripting. With PDO, JSON APIs, and frameworks like Laravel, PHP remains a powerful choice for building data-driven web applications and RESTful services.

What's next

In the next lessons, you'll dive deeper into each topic with hands-on examples and exercises.

Exercises

JSON Product API

easy

Create a PHP script that defines an array of products (id, name, price), converts it to JSON, and outputs it with the correct Content-Type header.

Expected Output:

[{"id":1,"name":"Widget","price":9.99},{"id":2,"name":"Gadget","price":24.99},{"id":3,"name":"Doohickey","price":4.99}]