Password Strength Check Script Class OOP Tutorial

This is a PHP class file creation and usage tutorial. Working with class files and objects opens up a wider range of software compartmentalization and helps you avoid instance collisions when many object instances simultaneously access a method or property. Object oriented programming should only be used when you have a practical need to reuse a scripted module, or share a complex scripted module with others in a common usage format. You can give people a few simple usage instructions and your class file to allow them to have all the programming power you provide in the class package. strongpass.php (the class file)

<?php
class strongpass {

    public function check($password){
	$response = "OK";
        if(strlen($password) < 8){
            $response = "Password must be at least 8 characters";
        } else if(is_numeric($password)){
            $response = "Password must contain at least one letter";
	} else if(!preg_match('#[0-9]#', $password)){
	    $response = "Password must contain at least one number";
	}
	/* 
	Additional checks you can accomplish as homework 
        - Make sure there is at least one lowercase letter
        - Make sure there is at least one uppercase letter
        - Make sure there is at least one symbol character
        */
        return $response;
    }

}
?>

demo.php (file that calls the strongpass class into action)

<?php
$password = "";
$status = "";
if(isset($_POST["password"])){
	$password = $_POST["password"];
	include_once("strongpass.php");
	$strongpass = new strongpass();
	$response = $strongpass->check($password);
	if($response != "OK"){
		$status = $response;
	} else {
		$status = "Password is strong so parsing can continue here.";
	}
}
?>
<h2>Class strongpass Demo</h2>
<form action="demo.php" method="post">
    <input name="password" type="password" value="<?php echo $password; ?>">
    <input type="submit" value="Check Password Strength">
</form>
<h3><?php echo $status; ?></h3>