PHP Class, set and get

<?php

class myClass{
    function __set($arg_1, $arg_2){
         echo "__set($arg_1, $arg_2)".PHP_EOL;
            if(is_array($arg_2)){
               echo "Setting array $arg_1 to $arg_2".PHP_EOL;
            }
            else {
               echo "setting string $arg_1 to $arg_2".PHP_EOL;
            }
            $this->$arg_1 = $arg_2;
    }

    function __get($arg){
         echo "showing $arg".PHP_EOL;
         return 'ERROR! variable does not exist';
    }
}


$mClass = new myClass();

$mClass->hello = 'this and that';

echo "Hi there: ". $mClass->hello.PHP_EOL;


$mClass->hello_again = array('this and that');

echo "Hi again: ".$mClass->hello_again.PHP_EOL;

echo $mClass->hello_again_2;