Implications of Instantiating Objects with Dynamic Variables in PHP

<?php
    $class_name = 'SomeClassName';
    $object = new $class_name;
?>

$classname = 'SomeClassName';
for ($x = 0; $x < 100000; $x++){
  $object = new $classname;
}

<?php

class Test {
    function __construct($x) {
    	echo $x;
    }
}

$class = 'Test';
$object = new $class('test'); // echoes "test"

?>

<?php

$class = "Test";
$args = array('a', 'b');
$ref = new ReflectionClass($class);
$instance = $ref->newInstanceArgs($args);

?>

<?php
$className = 'ClassName';

$className::someStaticMethod(); //doesn't work
?>

class Test {
    function testExt() {
    print 'hello from testExt :P';
    }
    function test2Ext()
    {
    print 'hi from test2Ext :)';
    }
}


$class = 'Test';
$method_1 = "testExt";
$method_2 = "test2Ext";
$object = new $class(); // echoes "test"
$object->{$method_2}(); // will print 'hi from test2Ext :)'
$object->{$method_1}(); // will print 'hello from testExt :P';