md5:may insert plain strings, and mysql convert them

[lse123]

Please answer these Questions came from reading a PHP textbook(Stobart, cengage):
A]
I GET IN MY SCRIPT
Strict Standards: Declaration of square::resize() should be compatible with that of shape::resize() in C:\xampp\htdocs\Stobart2008\ch17\square.php on line 17
WELL WHY IF USE
error_reporting(E_ALL);
THIS MESSAGE IS REMOVED?

THIS is warning And MUST BYPASSED? How correctly, I can bypass warnings?

 <?php
// File: example17-5.php
error_reporting(E_ALL);

function __autoload($class_name) {
    require_once $class_name . '.php';
}

$objRectangle = new rectangle(100,50, "rectangle.gif");
$objSquare = new square(100, "square.gif");
$objTriangle = new triangle(50,100, "triangle.gif");
$objEllipse = new ellipse(50,100, "ellipse.gif");

$arrShapes = array ($objRectangle,$objSquare,$objTriangle,$objEllipse);
foreach ($arrShapes as $objShape){
	$objShape->display();
	$objShape->area();
}
?>

B]
WHEN: globals=on, in php.ini =>
<input type="hidden" name="intOkay" value="1"/> = $intOkay
And when is of is not equal and must have:
<input type="hidden" name="intOkay" value="1"/> = $_POST[“intOkay”]
(or GET or REQUEST)
this is correct?
C]
To store md5 strings[actually passwords] to MySQL I must convert them from PHP or may insert plain strings, and mysql convert them?
Md5 code conversion of passwords are the same independently of website [url], or ver of PHP or ver of mysql, ALL are the same?