Why PHP class does not return `<h1>404</h1><p>Not found</p>`?

Why PHP class does not return <h1>404</h1><p>Not found</p>?

class checkid{
    public $title;
    public $content;
    function status(){
        $this->title='404';
        $this->content='Not found';
    }
}
$checkid=new checkid($url);
//$id=0;
((isset($id)) ? '' : $checkid->status().$title=开发者_高级运维$checkid->title.$content=$checkid->content);
//Why it does not return `<h1>404</h1><p>Not found</p>`?
echo "<h1>$title</h1><p>$content</p>";

Update: I know well to do it trough

if(isset($id)){}else{
    $checkid->status();
    $title=$checkid->title;
    $content=$checkid->content);
}

but I was worndering if it is possible to make it trough using

((isset($id)) ? '' : $checkid->status().$title=$checkid->title/*here $content break it down*//*.$content=$checkid->content*/);

1. Change isset('id') to isset($id).

2. The reason why you were getting <h1>404Not found</h1><p>Not found</p> was because you were concatenating the value of $content to the value of $title.

Also, you're code is quite a mess. I took the liberty of cleaning it up a bit:

class checkid
{
    public $title;
    public $content;
    function status()
    {
        $this->title='404';
        $this->content='Not found';
    }
}
$checkid=new checkid($url);
//$id=0;
if(!isset($id))
{
    $checkid->status();
    $title=$checkid->title;
    $content=$checkid->content;
}
echo "<h1>$title</h1><p>$content</p>";

You don't assign $title and $content

You probably want something like this

   $checkid->status();
   echo "<h1>$checkid->title</h1><p>$checkid->content</p>";

Because you are trying to (ab)use a conditional expression as a if statement.

if(!isset($id))
{

  $checkid->status();
  $title = $checkid->title;
  $content = $checkid->content;
}

What isset('id') means? do you mean isset($id) or isset($_GET['id']) ? And, btw,

$checkid->status().$title=$checkid->title.$content=$checkid->content);

is nonsens: you attach the return of status() to $checkid AND YOU ATTACH $title which is made equal to $checkid->title CONCATENATED to $content, and everythin is assigned $checkid->content

A bit confusing there