Question

Is it possible to instantiate a class from a string, without declaring another variable before ?

It’s usually done writing

$className = 'myClass'
$instance  = new $className();

but it could be handy to have it shorter like for example

$instance  = new ${'className'}();

The purpose is to have objects created (under condition) inside a loop without use of extra vars…

Edit : $className is dynamic, it is hard coded above to explain the situation

Answer 1

You could make a factory function (or class/method) that takes a class name as a parameter, and then call it with the result of your dynamic PHP code that generates the string. You might consider it a bit cleaner but it’s not going to save you any memory or speed.

class foo { }
function factory($class) { return new $class(); }

foreach (...) {
    $instance = factory(<some code that returns the string 'foo'>);
}