class Child extends ParentClass: inherit members; call the parent withparent::method().abstract class: cannot be instantiated; can declare abstract methods children must implement.interface: a contract of methods a class promises to implement (implements).trait: reusable methods you canuseinside several classes.final: prevents overriding or extending.
PHP OOP Inheritance & Interfaces
extends, abstract classes, interfaces and traits.
✍️ 2 exercises in this lessonKey Takeaways: PHP OOP Inheritance & Interfaces
Mastering PHP OOP Inheritance & Interfaces helps you write clean and reliable PHP code. Follow standard conventions, test edge cases, and keep logic simple. Try running the code example below and complete the exercises to build confidence.
PHP OOP Inheritance & Interfaces Code Example
PHP<?php
interface Shape { public function area(): float; }
trait Describes {
public function describe(): string {
return static::class . " with area " . round($this->area(), 2);
}
}
abstract class BaseShape implements Shape { use Describes; }
class Circle extends BaseShape {
public function __construct(private float $r) {}
public function area(): float { return M_PI * $this->r ** 2; }
}
class Rectangle extends BaseShape {
public function __construct(private float $w, private float $h) {}
public function area(): float { return $this->w * $this->h; }
}
foreach ([new Circle(2), new Rectangle(3, 4)] as $shape) {
echo $shape->describe() . "<br>";
}Output
Circle with area 12.57 Rectangle with area 12
Run this example on your own computer. The "Get Started" lesson shows how to set it up.
PHP OOP Inheritance & Interfaces Practice Exercises
Check what you learned in “PHP OOP Inheritance & Interfaces”.
/ 2 solved
Fill in the blank
Make Dog inherit from Animal.
class Dog Animal { }
✓ Correct!
Not quite. Try again.
Multiple choice
Which keyword reuses methods from a trait?
✓ Correct!
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to save your exercise progress.
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