The PHP you need to learn Elang#

This lesson explains the syntax used in the framework examples. It is a focused introduction, not a replacement for the complete PHP manual. You can run the small snippets in a practice.php file with php practice.php.

Variables and strings#

PHP variables begin with $. A semicolon ends a statement. The dot operator joins strings:

<?php
declare(strict_types=1);
$name = 'Ada';
echo 'Hello, '.$name.'!';

Expected output: Hello, Ada!. Quoted text is a string. 42 is an integer, and true is a boolean. Types matter when you read JSON or declare a typed function parameter.

Arrays#

An array can hold a list of values or named fields:

$tags = ['php', 'elang'];
$post = ['title' => 'A small beginning', 'published' => true];
echo $post['title'];

The => operator connects a key to a value. Elang's JSON responses often begin as PHP arrays. JSON is a text format sent over HTTP; it is not the same thing as the in-memory PHP array.

Functions and return values#

A function groups reusable behavior. Parameter and return types describe what it accepts and returns:

function greeting(string $name): string
{
    return 'Hello, '.$name.'!';
}
echo greeting('Ada');

return gives a value back to the caller. echo writes output directly. In an Elang handler, return a response instead of printing output yourself, so the kernel can set status codes and headers correctly.

Anonymous and arrow functions#

A route can receive an anonymous function:

$router->get('/hello', function () {
    return ['message' => 'Hello'];
});

An arrow function is a concise expression:

$router->get('/hello', fn () => ['message' => 'Hello']);

These examples have the same intended response. The function runs when a matching request reaches the handler, not merely because the route was registered.

Classes and objects#

A class describes an object. new creates an instance; -> accesses an instance method or property:

final class Greeter
{
    public function greet(string $name): string
    {
        return 'Hello, '.$name.'!';
    }
}
$greeter = new Greeter();
echo $greeter->greet('Ada');

A controller is a class used to handle requests. A service is a class with a reusable responsibility. Naming the responsibility makes code easier to understand as a project grows.

Constructors and dependency injection#

A constructor receives the dependencies an object needs:

final class WelcomeController
{
    public function __construct(private Greeter $greeter) {}
}

The short private Greeter $greeter syntax defines and stores the property. Elang's container can construct the Greeter and pass it into the controller. That is dependency injection; it does not require a global facade or a hidden variable.

Namespaces and use statements#

A qualified class name includes its namespace:

namespace App\Controllers;
use Elang\Http\Response;

use gives the file a shorter way to refer to an existing class. It does not download or install that class. Composer's autoloader locates the class file using the project's PSR-4 mapping.

In a generated application, App\Controllers\HelloController belongs in app/Controllers/HelloController.php. Match the spelling and capitalization, especially on Linux.

Static calls and class names#

Response::json(...) calls a static helper. HelloController::class produces the qualified class name as a string so the router can ask the container for it later. It does not immediately execute the controller.

Exceptions#

An exception interrupts normal execution. Elang converts supported HTTP and validation exceptions into responses. Unexpected exceptions are logged and become a safe 500 response in production.

Do not catch every exception and pretend the request succeeded. Use an expected status, inspect errors, and keep private details out of public output.

A quick self-check#

Can you explain why a route returns an array, why $name begins with a dollar sign, what -> and :: mean, and why a use statement does not install a package? If yes, continue with your first route. If a term is unfamiliar, keep the glossary open beside your editor.

For a broader language reference, read the official PHP tutorial.