PHP Traits

Traits are reusable code blocks that can be mixed into any class — PHP's solution to the limitation of single inheritance.

1 - Basic Trait

trait HasTimestamps {
    private string $createdAt;
    private string $updatedAt;

    public function touch(): void {
        $this->updatedAt = date("Y-m-d H:i:s");
    }

    public function getUpdatedAt(): string {
        return $this->updatedAt ?? "never";
    }
}

trait SoftDeletes {
    private bool $deleted = false;

    public function delete(): void   { $this->deleted = true; }
    public function restore(): void  { $this->deleted = false; }
    public function isDeleted(): bool { return $this->deleted; }
}

class Post {
    use HasTimestamps, SoftDeletes;
    public function __construct(public string $title) {}
}

$post = new Post("Hello World");
$post->touch();
$post->delete();
echo $post->isDeleted() ? "deleted" : "active"; // deleted

2 - Conflict Resolution

trait A { public function hello(): string { return "A"; } }
trait B { public function hello(): string { return "B"; } }

class C {
    use A, B {
        A::hello insteadof B;  // use A's version
        B::hello as helloB;    // keep B's as alias
    }
}

$c = new C;
echo $c->hello();   // A
echo $c->helloB();  // B