Zend Preparation | PHP Quiz (Learning Mode)

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Assuming every method call below returns an instance of an object, how can the following be re-written?

<?php
    $a = new MyClass();
    $b = $a->getInstance();
    $c = $b->doSomething();
?>

$c = ((MyClass)$a->getInstance())->doSomething();

$c = (MyClass)$a->getInstance();

$c = $a->getInstance()->doSomething();

This cannot be re-written in PHP5.

Explanation: Answer option C is correct.

This is testing "dereferencing returned objects." It can be possible only in the PHP5 and its later version, to call a method on a returned object. Dereferencing returned object facilitates us to call a function that return an object, you can treat the returned value of that function as an object from the calling line and access it directly. This also prevents you from creating temporary variables. Code for this function is given below:

<?php

class MyClass{
 function getInstance(){
 return $this;

 }

 function doSomething(){
 echo "Something";
 }
}

/*
$a = new MyClass();
$b = $a->getInstance();
$c = $b->doSomething();
*/

$a = new MyClass();
$c = $a->getInstance()->doSomething();

?>

Answer option A is incorrect. It will generate a syntax error.

Answer option D is incorrect. This cannot be done in PHP 4.

Answer option B is incorrect. It will generate a syntax error.

Reference: https://www.php.net/manual/en/language.types.object.php