PHP Math Pythagoras - php

Question

Okay, I've coded this pythagoras-solver kind of thing, and I was wondering any ways I could improve it, or make it more efficient?
<?php
$sides = array('1' => 'Hypotenuse',
'2' => 'Adjacent',
'3' => 'Opposite');
function createSideDropdown($name) {
global $sides;
$option = "<select name='".$name."'>";
if(!empty($sides)) {
foreach($sides as $id => $sideDesc) {
$option .= "<option value='".$id."'>".$sideDesc."</option>";
}
} else {
die("Error fetching sides!");
}
$option .= "</select>";
echo $option;
}
try {
if(!empty($_POST['submit'])) {
if(empty($_POST['val1']) || empty($_POST['val2'])) {
throw new Exception("Please enter an integer in both boxes.");
}
if(!is_numeric($_POST['val1']) || !is_numeric($_POST['val2'])) {
throw new Exception("One of the numbers you entered is not a valid integer.");
}
$val1 = $_POST['val1'];
$val2 = $_POST['val2'];
$val1numtype = $_POST['val1type'];
$val2numtype = $_POST['val2type'];
$val1nametype = $sides[$val1numtype];
$val2nametype = $sides[$val2numtype];
if($val1numtype == $val2numtype) {
throw new Exception("The two sides of the triangle must be different");
}
if($val1nametype == "Hypotenuse" || $val2nametype == "hypotenuse") {
// work out a small side
$bignum = max($val1, $val2);
$smallnum = min($val1, $val2);
$sqTotal = ($bignum * $bignum) - ($smallnum * $smallnum);
$total = sqrt($sqTotal);
echo $bignum."² - ".$smallnum."² = ".$sqTotal."<br />
√".$sqTotal." = ".$total.$_POST['mes'];
} else {
// work out the hypotenuse
$sq1 = $val1 * $val1;
$sq2 = $val2 * $val2;
$sqTotal = $sq1 + $sq2;
$total = sqrt($sqTotal);
echo $val1."² + ".$val2."² = ".$sqTotal."<br />
√".$sqTotal." = ".$total.$_POST['mes'];
}
echo "<br /><br />"; // Seperate the working out from the input
}
} catch(Exception $e) {
echo $e->getMessage()."<br/><br/>";
}
?>
<form method='POST' action='index.php'>
Value 1: <input type='text' name='val1' />
<?php createSideDropdown("val1type"); ?>
<br /><br />
Value 2: <input type='text' name='val2' />
<?php createSideDropdown("val2type"); ?>
<br />
<select name="mes">
<option name="mm">mm</option>
<option name="cm">cm</option>
<option name="m">m</option>
<option name="cm">km</option>
</select>
<br />
<input type="submit" name="submit" />
</form>
?>

Answer 1

Well, one thing you can certainly do is:
HTML on its own and PHP on its own - separate that. And then, I would continue having a look at the rest.
Also, you could do your exceptions with JavaScript - I mean, use JavaScript to parse the text fields and write the errors with JavaScript. Rather than always submitting the form. - Still you should parse the fields in PHP as well.
Then, make a class out of it and make a proper documentation of it such as
/**
* This method does bla
* #param Int a
*/
Don't use globals - could be done with class attributes.