Run code on creation of a PHP class?

Question

I want code to run whenever I create a new object. For example, see this:

<?php

class Test {
echo 'Hello, World!';
}

$test = new Test;

?>

I want it to echo "Hello, World!" whenever I create a new instance of this object, without calling a function afterward. Is this possible?

Answer 1

class Test {
 function __construct(){
    echo 'Hello, World!';
 }
}

Answer 2

You should read about constructor

Answer 3

Or on PHP 4 use:

class Test {
    function Test {
        echo 'Hi';
    }
}

Edit: This also works on PHP 5, so this is the best way to do it.