__serialize and __unserialize in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define the __serialize method that returns the object's data as an array.

PHP

<?php
class User {
    private $name;
    private $age;

    public function __construct($name, $age) {
        $this->name = $name;
        $this->age = $age;
    }

    public function __serialize(): array {
        return [1];
    }
}
?>

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

Aarray("name" => $this->name, "age" => $this->age)

B["name" => $this->name, "age" => $this->age]

C[$this->name, $this->age]

Dserialize($this)

Attempts:

3 left

💡 Hint

Common Mistakes

Returning a serialized string instead of an array.

Returning a numeric array without keys.

The __serialize method must return an array of the object's data. Using array() syntax is correct here.

2fill in blank

medium

Complete the code to define the __unserialize method that restores the object's properties from the given data array.

PHP

<?php
class User {
    private $name;
    private $age;

    public function __unserialize(array $data): void {
        $this->name = $data[[1]];
        $this->age = $data["age"];
    }
}
?>

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

A1

B"name"

C0

D"age"

Attempts:

3 left

💡 Hint

Common Mistakes

Using numeric indexes instead of string keys.

Mixing up keys for name and age.

The __unserialize method receives an array with keys matching the property names. So to restore $name, use the key "name".

3fill in blank

hard

Fix the error in the __serialize method to correctly return the object's data as an array.

PHP

<?php
class Product {
    private $id;
    private $price;

    public function __serialize(): array {
        return [1];
    }
}
?>

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

Aarray("id", $this->id, "price", $this->price)

Bserialize(["id" => $this->id, "price" => $this->price])

C["id" => $this->id, "price" => $this->price]

D[$this->id, $this->price]

Attempts:

3 left

💡 Hint

Common Mistakes

Returning a serialized string instead of an array.

Returning a numeric array without keys.

The __serialize method must return an associative array with keys and values, not a serialized string or a numeric array.

4fill in blank

hard

Fill both blanks to complete the __unserialize method that restores the object's properties from the data array.

PHP

<?php
class Product {
    private $id;
    private $price;

    public function __unserialize(array $data): void {
        $this->id = $data[[1]];
        $this->price = $data[[2]];
    }
}
?>

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

A"id"

B"price"

C0

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using numeric indexes instead of string keys.

Swapping the keys for id and price.

The __unserialize method uses the keys "id" and "price" to restore the respective properties from the data array.

5fill in blank

hard

Fill all three blanks to complete the class with __serialize and __unserialize methods that handle the properties correctly.

PHP

<?php
class Book {
    private $title;
    private $author;
    private $pages;

    public function __serialize(): array {
        return [[1] => $this->title, [2] => $this->author, [3] => $this->pages];
    }

    public function __unserialize(array $data): void {
        $this->title = $data["title"];
        $this->author = $data["author"];
        $this->pages = $data["pages"];
    }
}
?>

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

A"title"

B"author"

C"pages"

D"book"

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect or inconsistent keys.

Using a single key for all properties.

The __serialize method returns an associative array with keys matching the property names: "title", "author", and "pages".