How can I display an alert/ message in object-oriented PHP?

Question

Currently I have used JavaScript to display an alert to notify that the execution was successful, merely for testing purposes. How can I do that in PHP object-oriented style?

I've tried:

public $msg='May the force be with you.';
$this->msg = new msg();

...but result was a white blank page. JavaScript piece I tried works well though. Below is the complete code:

<?php
class database {
    public $mysql;
        private $db_host='localhost';
        private $db_username='admin';
        private $db_password='password';
        private $db_name='db';

    function __construct() {
        $this->mysql = new mysqli($this->db_host, $this->db_username, $this->db_password, $this->db_name) or die (mysql_error() ); {
            echo 
            "<script type='text/javascript'>
            alert ('The Force will be with you, always.');
            </script>";
        }
    }
    function __destruct() {
        $this->mysql->close();
    }
}
?>

Answer 1

1. PHP is server-side, which means it runs on a machine different from the user.

2. Javascript is client-side, which means it runs on the user's machine.

3. The server should have no control over anything on the user's machine.

Therefore, an alert box from PHP is not possible. :)

You've got to stick with Javascript, which only runs client-side. That, or echo plaintext out onto the document itself.

FYI, this relationship brings up other fun questions, like, "how can Javascript talk to the server" (answer:ajax) and "can a script talk to another computer" (answer: yes, but it's not supposed to).

Answer 2

Try this code:

<?php
class database {
    public $mysql;
        private $db_host='localhost';
        private $db_username='admin';
        private $db_password='correcthorsebatterystaple';
        private $db_name='projekt';

    function __construct() {
        $this->mysql = new mysqli($this->db_host, $this->db_username, $this->db_password, $this->db_name) or die (mysql_error() );
    }
   function pri()
    {
            echo 
            "<script type='text/javascript'>
            alert ('The Force will be with you, always.');
            </script>";
        }
    function __destruct() {
        $this->mysql->close();
    }
}

$msg=new database();
$msg->pri();
?>

Answer 3

In PHP, you can do print_r() for any variable (or var_dump() ) to see the contents of an object or array, etc.

Doing this will dump the contents directly on the page source (but not as a browser popup).