Null object pattern: Difference between revisions

Revision as of 07:17, 14 November 2021

Revision as of 11:01, 14 January 2022

Line 385:

{

public function makeSound()

{

echo "Woof...\n";

}

}

Line 393:

{

public function makeSound()

{

echo "Meowww...\n";

}

}

Line 401:

{

public function makeSound()

{

// silence...

}

Line 407:

$animalType = 'elephant';

switch($animalType) {

function makeAnimalFromAnimalType(string $animalType): Animal

case 'dog':

{

$animal = new Dog();

switch($animalType) {

break;

case 'catdog':

$animal = return new CatDog();

break;case 'cat':

return new Cat();

default:

$animal = new NullAnimal();default:

break return new NullAnimal();

}

}

makeAnimalFromAnimalType($animalanimalType)->makeSound(); // ..the null animal makes no sound

function animalMakeSound(Animal $animal): void

{

$animal = new Dog->makeSound();

}

foreach ([

makeAnimalFromAnimalType('dog'),

makeAnimalFromAnimalType('NullAnimal'),

makeAnimalFromAnimalType('cat'),

] as $animal) {

// That's also reduce null handling code

animalMakeSound($animal);

}

$animal->makeSound(); // ..the null animal makes no sound

</syntaxhighlight>