Constructor inheritance in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a constructor in the parent class.

PHP

<?php
class ParentClass {
    public function [1]() {
        echo "Parent constructor called\n";
    }
}
?>

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

AParentClass

Bconstruct

C__construct

Dinit

Attempts:

3 left

💡 Hint

Common Mistakes

Using a method name without underscores like 'construct'.

Using the class name as constructor (old PHP style).

The constructor method in PHP is named __construct. This special method is called automatically when an object is created.

2fill in blank

medium

Complete the code to call the parent constructor from the child class.

PHP

<?php
class ChildClass extends ParentClass {
    public function __construct() {
        [1]();
        echo "Child constructor called\n";
    }
}
?>

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

Aparent::ParentClass

Bthis->__construct

Cself::__construct

Dparent::__construct

Attempts:

3 left

💡 Hint

Common Mistakes

Calling self::__construct() which calls the current class constructor recursively.

Using this instead of parent.

To call the parent class constructor in PHP, use parent::__construct().

3fill in blank

hard

Fix the error in the child constructor to properly inherit the parent constructor.

PHP

<?php
class ChildClass extends ParentClass {
    public function __construct() {
        [1];
        echo "Child constructor called\n";
    }
}
?>

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

Aparent::__construct()

Bparent.__construct()

Cparent->__construct()

Dparent::__construct

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting parentheses when calling the method.

Using arrow -> or dot . instead of double colon.

The correct syntax to call the parent constructor is parent::__construct() with parentheses to invoke the method.

4fill in blank

hard

Fill both blanks to create a child constructor that calls the parent constructor and sets a property.

PHP

<?php
class ChildClass extends ParentClass {
    public $name;
    public function __construct($name) {
        [1]();
        $this->[2] = $name;
    }
}
?>

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

Aparent::__construct

Bname

Cparent::__construct()

Dname()

Attempts:

3 left

💡 Hint

Common Mistakes

Calling parent constructor without parentheses.

Using incorrect property name or syntax.

The child constructor calls the parent constructor with parent::__construct() and sets the property $name using $this->name = $name;.

5fill in blank

hard

Fill all three blanks to complete the child constructor that calls the parent constructor with a parameter and sets a property.

PHP

<?php
class ParentClass {
    public function __construct($id) {
        echo "Parent constructor with ID: $id\n";
    }
}

class ChildClass extends ParentClass {
    public $name;
    public function __construct($id, $name) {
        [1]([2]);
        $this->[3] = $name;
    }
}
?>

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

Aparent::__construct

B$id

Cname

Dparent::__construct()

Attempts:

3 left

💡 Hint

Common Mistakes

Calling parent constructor without passing the parameter.

Using incorrect syntax for calling the parent constructor.

The child constructor calls the parent constructor passing $id using parent::__construct($id); and sets the $name property.