<?php

class Preview
{
	
	private $id;
	
	function __construct($id) {
		$this->id = $id;
	}
	
	function show()
	{
		echo $this->id.' ';
	}
	
}

for ($i = 0; $i < 4; $i++){
	$preview = new Preview($i);
    $preview->show();
}