Abstract classes and methods in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare an abstract class named Vehicle.

PHP

<?php
abstract class [1] {
}
?>

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

AVehicle

Bvehicle

Cabstract

Dclass

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase 'vehicle' instead of 'Vehicle'.

Writing 'abstract' as the class name.

Omitting the class name.

The keyword abstract is used before the class name to declare an abstract class. The class name should be Vehicle as specified.

2fill in blank

medium

Complete the code to declare an abstract method named startEngine inside the abstract class.

PHP

<?php
abstract class Vehicle {
    public abstract function [1]();
}
?>

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

Astartengine

Bstart_engine

CStartEngine

DstartEngine

Attempts:

3 left

💡 Hint

Common Mistakes

Using all lowercase or underscores in the method name.

Capitalizing the first letter incorrectly.

By convention, method names in PHP use camelCase. The method should be named exactly startEngine as given.

3fill in blank

hard

Fix the error in the code by completing the method declaration correctly.

PHP

<?php
abstract class Vehicle {
    public abstract function [1]();
}
?>

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

AstartEngine

Babstract startEngine

Cabstract function startEngine

DstartEngine()

Attempts:

3 left

💡 Hint

Common Mistakes

Including keywords like 'abstract' or 'function' in the blank.

Adding parentheses in the blank.

In an abstract class, to declare an abstract method, you must use the abstract keyword before the function. However, here the blank is only for the method name. The correct method declaration is public abstract function startEngine();. Since the code already has public abstract function, the blank should only be the method name startEngine.

4fill in blank

hard

Fill both blanks to complete the class that extends the abstract class and implements the abstract method.

PHP

<?php
class Car extends [1] {
    public function [2]() {
        echo "Engine started";
    }
}
?>

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

AVehicle

BstartEngine

Cstartengine

Dvehicle

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase 'vehicle' instead of 'Vehicle'.

Incorrect method name casing.

The class Car extends the abstract class Vehicle (capitalized). It must implement the abstract method startEngine exactly as declared.

5fill in blank

hard

Fill all three blanks to create an instance of the class and call the implemented method.

PHP

<?php
$car = new [1]();
$car->[2]();
echo $car instanceof [3] ? "Yes" : "No";
?>

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

ACar

BstartEngine

CVehicle

Dcar

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase class names.

Calling a method that does not exist.

Checking instance against wrong class.

We create a new object of class Car, call its method startEngine, and check if it is an instance of the abstract class Vehicle.