{ } mark in echo "{$e->getMessage()}"
<p>I read about this <a href="http://net.tutsplus.com/tutorials/php/the-ins-and-outs-of-php-exceptions/comment-page-1/" rel="nofollow">Article</a> 
I wondering about this part: </p>

<pre><code>try {
    //First try getting our user numero uno
    $user = new User(1);

    //Then, let's try to get the exception
    $user2 = new User('not numeric');
} catch( Exception $e ) {
    echo "Donkey Kong has caught an exception: {$e-&gt;getMessage()}";
}
</code></pre>

<p>why <code>{$e-&gt;getMessage()}</code> must be covered in bracket?<br>
Is there any link explanation on php manual about this?</p>

<p>i know if we don't put bracket it will show error, but want i want is to get the explanation why bracket is needed.</p>

<blockquote>
  <p>Notice: Undefined property: Exception::$getMessage</p>
</blockquote>
