PHP Anonymous Classes: Patterns and Examples

Anonymous classes can implement interfaces or extend classes for local adapters and test doubles.

The examples below begin with the core behavior, then move to an application-oriented use.

How PHP Anonymous Classes: Patterns and Examples Works

Anonymous classes can implement interfaces or extend classes for local adapters and test doubles.

Example 1: Basic Usage

This example uses a small input to make the main behavior visible.

<?php

interface Translator { public function translate(string $word): string; }
$translator = new class implements Translator { public function translate(string $word): string { return strtoupper($word); } };
echo $translator->translate("welcome");

Output:

WELCOME

Anonymous classes can implement interfaces or extend classes for local adapters and test doubles.

Example 2: A Different Input

A different set of values shows the same operation in another situation.

<?php

$formatter = new class("USD") { public function __construct(private string $currency) {} public function format(int $amount): string { return $amount . " " . $this->currency; } };
echo $formatter->format(25);

Output:

25 USD

Do not hide large production components inside anonymous classes; keep the implementation narrow.

Practical Example: Applying the Feature

This example shows an application-style use of the feature, with its surrounding setup visible.

<?php

interface CacheStore { public function get(string $key): ?string; }
$cache = new class implements CacheStore { public function get(string $key): ?string { return $key === "theme" ? "dark" : null; } };
echo $cache->get("theme");

Output:

dark

The code is shown for learning. Adjust the class names, inputs and error handling to suit your application.

Important Behavior and Edge Cases

• Do not hide large production components inside anonymous classes; keep the implementation narrow.
• Anonymous classes can implement interfaces or extend classes for local adapters and test doubles.
• Observe differences in empty inputs, invalid states and optional extension availability where relevant.

Comparison With Related Approaches

Common Beginner Mistakes

Key Takeaways

• Anonymous classes can implement interfaces or extend classes for local adapters and test doubles.
• Do not hide large production components inside anonymous classes; keep the implementation narrow.
• Use the example that matches the values, runtime version and dependencies in your application.

PHP Anonymous Classes: Patterns and Examples is useful when its behavior matches the data structure and lifecycle of your PHP application. Choose it with a clear understanding of its preconditions and returned values.