Why inheritance is needed in PHP - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a class that inherits from another class.

PHP

<?php
class Animal {
    public function sound() {
        echo "Some sound";
    }
}

class Dog extends [1] {
}

$dog = new Dog();
$dog->sound();
?>

Drag options to blanks, or click blank then click option'

ADog

BAnimal

CSound

DPet

Attempts:

3 left

💡 Hint

Common Mistakes

Using the child class name instead of the parent class name after extends.

Forgetting to use the extends keyword.

The Dog class inherits from the Animal class using the extends keyword.

2fill in blank

medium

Complete the code to override the method in the child class.

PHP

<?php
class Animal {
    public function sound() {
        echo "Some sound";
    }
}

class Cat extends Animal {
    public function [1]() {
        echo "Meow";
    }
}

$cat = new Cat();
$cat->sound();
?>

Drag options to blanks, or click blank then click option'

Asound

Bnoise

Cvoice

DmakeSound

Attempts:

3 left

💡 Hint

Common Mistakes

Changing the method name so it does not override the parent method.

Forgetting to define the method in the child class.

The child class overrides the sound method to provide its own implementation.

3fill in blank

hard

Fix the error in the code to call the parent class method inside the child class method.

PHP

<?php
class Bird {
    public function sound() {
        echo "Chirp";
    }
}

class Parrot extends Bird {
    public function sound() {
        [1]::sound();
        echo " and Talk";
    }
}

$parrot = new Parrot();
$parrot->sound();
?>

Drag options to blanks, or click blank then click option'

ABird

Bself

Cparent

D$this

Attempts:

3 left

💡 Hint

Common Mistakes

Using self or class name instead of parent to call the parent method.

Using $this which calls the current class method causing recursion.

Use parent::sound() to call the parent class method inside the child class.

4fill in blank

hard

Fill both blanks to create a class that inherits and adds a new method.

PHP

<?php
class Vehicle {
    public function start() {
        echo "Starting vehicle";
    }
}

class Car [1] Vehicle {
    public function [2]() {
        echo "Driving car";
    }
}

$car = new Car();
$car->start();
$car->drive();
?>

Drag options to blanks, or click blank then click option'

Aextends

Bimplements

Cdrive

Drun

Attempts:

3 left

💡 Hint

Common Mistakes

Using implements instead of extends for class inheritance.

Naming the new method incorrectly.

The Car class inherits from Vehicle using extends and adds a new method drive.

5fill in blank

hard

Fill all three blanks to create a class that inherits, overrides a method, and calls the parent method.

PHP

<?php
class Computer {
    public function boot() {
        echo "Booting computer";
    }
}

class Laptop [1] Computer {
    public function [2]() {
        [3]::boot();
        echo " with battery";
    }
}

$laptop = new Laptop();
$laptop->boot();
?>

Drag options to blanks, or click blank then click option'

Aextends

Bboot

Cparent

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong keywords for inheritance.

Not matching the method name when overriding.

Calling the parent method incorrectly.

The Laptop class inherits from Computer using extends, overrides the boot method, and calls the parent method with parent::boot().