Strategy pattern in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare the Strategy interface.

PHP

<?php
interface [1] {
    public function execute();
}
?>

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

AStrategy

BContext

CAlgorithm

DExecutor

Attempts:

3 left

💡 Hint

Common Mistakes

Using a class name instead of interface.

Naming the interface 'Context' or other unrelated names.

The interface that defines the strategy method is named Strategy.

2fill in blank

medium

Complete the code to implement a concrete strategy class.

PHP

<?php
class ConcreteStrategyA implements [1] {
    public function execute() {
        echo "Strategy A executed.";
    }
}
?>

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

AStrategy

BExecutor

CContext

DAlgorithm

Attempts:

3 left

💡 Hint

Common Mistakes

Implementing a class instead of an interface.

Using wrong interface name.

The concrete strategy class must implement the Strategy interface.

3fill in blank

hard

Fix the error in the Context class constructor to accept a strategy.

PHP

<?php
class Context {
    private $strategy;

    public function __construct([1] $strategy) {
        $this->strategy = $strategy;
    }
}
?>

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

AConcreteStrategyA

BExecutor

CContext

DStrategy

Attempts:

3 left

💡 Hint

Common Mistakes

Using a concrete class type hint instead of the interface.

Using the class name 'Context' as type hint.

The constructor should accept a parameter typed as the Strategy interface to allow any strategy implementation.

4fill in blank

hard

Complete the code to call the strategy's execute method inside Context.

PHP

<?php
class Context {
    private $strategy;

    public function __construct(Strategy $strategy) {
        $this->strategy = $strategy;
    }

    public function executeStrategy() {
        $this->strategy->execute[1];
    }
}
?>

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

A->

B()

C.

D;

Attempts:

3 left

💡 Hint

Common Mistakes

Using dot operator instead of ->.

Forgetting parentheses when calling the method.

To call a method on an object in PHP, use the -> operator followed by parentheses () for the method call.

5fill in blank

hard

Fill all three blanks to create a Context with a ConcreteStrategyA and execute it.

PHP

<?php
$strategy = new [1]();
$context = new Context([2]);
$context->[3]();
?>

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

AConcreteStrategyA

B$strategy

CexecuteStrategy

DStrategy

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the class name instead of the object to Context.

Calling a non-existent method on Context.

First, create a new ConcreteStrategyA object, then pass it to the Context constructor, and finally call executeStrategy() on the context.