Implementing Interfaces
Use the implements keyword after the class name. The class must implement every method declared in the interface with matching signatures.
PHP
Intermediate
5 min read
Implementing an Interface
Example
<?php
interface Serializable {
public function serialize(): string;
public function unserialize(string $data): void;
}
class User implements Serializable {
public function __construct(
private string $name,
private string $email
) {}
public function serialize(): string {
return json_encode(["name" => $this->name, "email" => $this->email]);
}
public function unserialize(string $data): void {
$obj = json_decode($data, true);
$this->name = $obj["name"];
$this->email = $obj["email"];
}
} Pro Tip
PHP 8 allows covariant return types in interface implementations — the implementing method can return a more specific type.