matejkramny/caculator.php

## caculator.php
<?php

// NEVER DO THIS - BAD
//extract($_GET);
ini_set('display_errors', '1');
error_reporting(E_STRICT | E_ALL);

$prod = 0; $x = 0; $y = 0;
$action = "not set";
$formula = "";

if (isset($_GET['action']) && isset($_GET['x']) && isset($_GET['y'])) {
   $action = $_GET['action'];
   $x = floatval($_GET['x']);
   $y = floatval($_GET['y']);

   if (is_nan($x) || is_nan($y)) {
      $x = 0;
      $y = 0;
   }

   switch ($action) {
      case 'add':
         $prod = $x + $y;
         $formula = "x + y";
         break;
      case 'subtract':
      	$prod = $x - $y;
         $formula = "x - y";
         break;
      case 'multiply':
         $prod = $x * $y;
         $formula = "x * y";
         break;
      case 'divide':
         $prod = $x / $y;
         $formula = "x / y";
         break;
   }
}

?>

<html>
   <head>
      <title>PHP Calculator Example</title>
   </head>

   <body>

      <h3>PHP Calculator (Version 1)</h3>
      <p>Multiply two numbers and output the result</p>

      <form>

         x = <input type="text" name="x" size="5" value="<?php print $x; ?>"/>
         y =  <input type="text" name="y" size="5" value="<?php  print $y; ?>"/>

		<select name="action">
         <option value="add">Add</option>
         <option value="subtract">Subtract</option>
         <option value="multiply">Multiply</option>
         <option value="divide">Divide</option>
      </select>
      <button type="submit">Calculate</button>
      </form>

      <!-- print the result -->
      <p><?php print $formula; ?> = <?php print $prod; ?></p>
   </body>
</html>
	<?php

	// NEVER DO THIS - BAD
	//extract($_GET);
	ini_set('display_errors', '1');
	error_reporting(E_STRICT \| E_ALL);

	$prod = 0; $x = 0; $y = 0;
	$action = "not set";
	$formula = "";

	if (isset($_GET['action']) && isset($_GET['x']) && isset($_GET['y'])) {
	$action = $_GET['action'];
	$x = floatval($_GET['x']);
	$y = floatval($_GET['y']);

	if (is_nan($x) \|\| is_nan($y)) {
	$x = 0;
	$y = 0;
	}

	switch ($action) {
	case 'add':
	$prod = $x + $y;
	$formula = "x + y";
	break;
	case 'subtract':
	$prod = $x - $y;
	$formula = "x - y";
	break;
	case 'multiply':
	$prod = $x * $y;
	$formula = "x * y";
	break;
	case 'divide':
	$prod = $x / $y;
	$formula = "x / y";
	break;
	}
	}

	?>

	<html>
	<head>
	<title>PHP Calculator Example</title>
	</head>

	<body>

	<h3>PHP Calculator (Version 1)</h3>
	<p>Multiply two numbers and output the result</p>

	<form>

	x = <input type="text" name="x" size="5" value="<?php print $x; ?>"/>
	y = <input type="text" name="y" size="5" value="<?php print $y; ?>"/>

	<select name="action">
	<option value="add">Add</option>
	<option value="subtract">Subtract</option>
	<option value="multiply">Multiply</option>
	<option value="divide">Divide</option>
	</select>
	<button type="submit">Calculate</button>
	</form>

	<!-- print the result -->
	<p><?php print $formula; ?> = <?php print $prod; ?></p>
	</body>
	</html>