Methods and $this keyword in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to call the method inside the class using $this.

PHP

<?php
class Car {
    public function start() {
        echo "Car started";
    }
    public function run() {
        $this->[1]();
    }
}
$car = new Car();
$car->run();
?>

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

Astop

Brun

Cstart

Ddrive

Attempts:

3 left

💡 Hint

Common Mistakes

Using the method name without $this->

Calling a method that does not exist

Inside a class, to call another method, you use $this->methodName(). Here, $this->start() calls the start method.

2fill in blank

medium

Complete the code to access the property inside the method using $this.

PHP

<?php
class Person {
    public $name = "Alice";
    public function greet() {
        echo "Hello, " . $this->[1];
    }
}
$person = new Person();
$person->greet();
?>

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

Aname

Bhello

Cgreet

Dage

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to access property without $this->

Using a wrong property name

Inside the method, $this->name accesses the property 'name' of the current object.

3fill in blank

hard

Fix the error in the method to correctly return the object's property using $this.

PHP

<?php
class Book {
    public $title = "PHP Basics";
    public function getTitle() {
        return [1]->title;
    }
}
$book = new Book();
echo $book->getTitle();
?>

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

Athis

B$this

C$self

Dself

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'this' without $ sign

Using 'self' which refers to the class, not the object instance

In PHP, $this refers to the current object inside methods. So, return $this->title; is correct.

4fill in blank

hard

Fill both blanks to create a method that sets the object's property using $this.

PHP

<?php
class Laptop {
    public $brand;
    public function setBrand([1]) {
        $this->[2] = $brand;
    }
}
$laptop = new Laptop();
$laptop->setBrand("Dell");
echo $laptop->brand;
?>

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

Astring $brand

Bbrand

Cmodel

Dprice

Attempts:

3 left

💡 Hint

Common Mistakes

Not using a parameter in the method

Assigning to a wrong property name

The method parameter should be 'string $brand' to accept a string argument. Inside the method, $this->brand sets the object's property.

5fill in blank

hard

Fill all three blanks to create a method that updates and returns the object's property using $this.

PHP

<?php
class Phone {
    public $color = "Black";
    public function changeColor([1]) {
        $this->[2] = $newColor;
        return $this->[3];
    }
}
$phone = new Phone();
echo $phone->changeColor("Red");
?>

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

Astring $newColor

Bcolor

DnewColor

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong parameter name

Returning a variable instead of the property

The method parameter is 'string $newColor'. Inside the method, $this->color is updated and returned.