用于从方法创建新对象的Nice Syntaxe

Question

There is a shortcut method to create an object from a method that return a string?

For the moment, I used that :

class MyClass {

    /**
     * @return string
     */
    public function getEntityName() {
        return 'myEntityName';
    }
}

$myClassInstance = new MyClass();

// Need to get string
$entityName = $myclassInstance->getEntityName();

// And after I can instantiate it
$entity = new $entityName();

Answer 1

There is short-cut syntax for getting the string but not for creating the object from the string to date in PHP. See the following code in which I also include a 'myEntityName' class:

<?php

class myEntityName {
    public function __construct(){
        echo "Greetings from " . __CLASS__,"
";
    }
}
class MyClass {

    /**
     * @return string
     */
    public function getEntityName() {
        return 'myEntityName';
    }
}

$entityName = ( new MyClass() )->getEntityName();
$entity = new $entityName();

With one line the code instantiates a MyClass object and executes its getEntityName method which returns the string $entityName. Interestingly, if I replace my one-liner with the following it fails in all versions of PHP except for the HipHop Virtual Machine (hhvm-3.0.1 - 3.4.0):

$entityName = new ( ( new MyClass() )->getEntityName() );