Classe upload, refatorada para fazer múltiplo upload.

Upload.php

<?php

namespace Upload;
class Upload
{
	public  $definePath = '';
	private $path;
	
	public function __construct($definePath, $path = 'arquivos/')
	{
		$this->path = dirname(__FILE__) . '/../../common/'.$path;
		$this->definePath = $definePath;
	}
	
	public function upload($arq = 'arquivo')
	{
           $tmp      =      $_FILES[$arq]["tmp_name"];
	   $nameFile =      $_FILES[$arq]["name"];
		
		
		
                try
		{
		 
		  if(is_array($tmp) && is_array($nameFile))
		  {  
		    for($i = 0; $i <= count($tmp) && $i <= count($nameFile); $i++)
		    {
		    	if(!empty($tmp[$i]) && !empty($nameFile[$i]))
		    	{
		    		
		    		$rand = mt_rand(0, 99999);
		    		$nameFile[] = str_replace(" ", "", $nameFile[$i]);
		    		$nameFileModified[] = $rand.$nameFile[$i];
		    		$place[] = $this->diretorio().$nameFileModified[$i]; // ../imagem/subPasta/nomeArquivo
		    		move_uploaded_file($tmp[$i], $place[$i]);
		    		$placeFinal[] = str_replace($this->path, '', $place[$i]); 
		    	}
		    	
		    }
		  }
		  return $placeFinal;
		}
		catch(Exception $e)
		{
			echo 'Houve um erro durante o upload.: ' .$e->getMessage();
		}
		
	}
	
	public function diretorio()
	{   
		if(!is_dir($this->path))
		{
		  mkdir($this->path, 0777);
		  chmod($this->path, 0777);
		} 

		$finalPath = $this->path.$this->definePath.'/';
			 
		if(is_dir($finalPath))
		{
		  chmod($finalPath, 0777);
		  return $finalPath;
		}
		else
		{
		  if(mkdir($finalPath, 0777))
		  {
		     chmod($finalPath, 0777);
		     return $finalPath;
		  }
		}
	}
}

use.php

<?php

$u = new Upload('teste');
$content = '<form action="" method="POST" enctype="multipart/form-data">
              Send these files:<br />
             <input name="arquivo[]" type="file" /><br />
             <input name="arquivo[]" type="file" /><br />
		     <input name="arquivo[]" type="file" /><br />
             <input type="submit" value="Send files" />
            </form>';

echo $content;

var_dump($u->upload());
var_dump($u->diretorio());