PHP issue with Dropdown list - php

Question

I have created a populated dropdown list in HTML. When the two dropdowns have been selected, the form posts to 'calculate.php' where the php script echoes out the selected values from the dropdowns.
<form action="calculate.php" method='POST'>
<select name="Phones">
<option value="Lumia800">Nokia Lumia 800</option>
<option value="iPhone">Apple iPhone 4s</option>
<option value="GalaxyS2">Samsung Galaxy S2</option>
<option value="Bold9900">Blackberry Bold 9900</option>
<option value="SensationXE">HTC Sensation XE</option>
<option value="XperiaS">Sony Ericsson Xperia S</option>
</select>
<select name="Network">
<option value="Orange">Orange</option>
<option value="Vodafone">Vodafone</option>
<option value="O2">O2</option>
<option value="Three">Three</option>
</select>
<input type="submit" />
</form>
In this one example, 'calculate.php' echoes the selected dropdown values.
<?php
$pref=$_POST['Phones'];
$pref1=$_POST['Network'];
$Orange="5";
if ($pref1 == "Orange")
{
$total1 = $Orange;
}
$Lumia800="10";
if ($pref == "Lumia800")
{
$total = $Lumia800 + $Orange;
}
echo $total;
?>
This example output is '15'
The aim of this example is to eventually create a simple phone package system, with this set of code adding the price of the phone, the network costs, and other variables together for a final total of how much it would cost when the user submits it.
The problem I have is that I want to add each variable from the corresponding dropdown boxes ("Phones" and "Network" for example) against each other. Is my example going to be too over complicated for such a simple script? Is there a more refined method to get the results that I want?
Thanks,
JB.

Answer 1

You should define arrays for each select that contains all prices.
$phone_prices = array("Lumia800" => 10, "iPhone" => 42);
$network_prices = array("Orange" => 5, ...);
And then you coud simply do something like
$price = $phone_prices[$pref] + $network_prices[$pref1];
But this is not really safe, make sure $pref and $pref1 are existing indexes in their respective array.

Answer 2

It will work but might be complicated. I would suggest changing over to a switch statement instead.
$total = 0
switch ($pref) {
case "Orange":
$total += 5;
break;
case "O2":
$total += 8;
break;
}
Same switch structure would be for the $pref1 or network variable.

Answer 3

<form action="calculate.php" method='POST'>
<select name="Phones">
<option value="123">Nokia Lumia 800</option>
<option value="234">Apple iPhone 4s</option>
<option value="12">Samsung Galaxy S2</option>
<option value="32">Blackberry Bold 9900</option>
<option value="432">HTC Sensation XE</option>
<option value="12">Sony Ericsson Xperia S</option>
</select>
<select name="Network">
<option value="42">Orange</option>
<option value="34">Vodafone</option>
<option value="23">O2</option>
<option value="34">Three</option>
</select>
<input type="submit" />
</form>
and
<?php
echo $_POST['Network'] + $_POST['Phones'];
?>
might be a lot simpler in that case, but that of course depends on the exact situation where you need this.

Answer 4

G'day mate.
You could for one, create an array of mapping from Phones => Price and Network => Price
example:
<?php
$phones = array(
'Lumia800' => 10,
'iPhone' => 15,
'GalaxyS2' => 30,
// rest of the phones with price
);
$networks = array(
'Orange' => 10,
'Vodafone' => 15,
'Three' => 3,
'O2' => 8
);
then validate user input
if(!empty($phones[$pref])) && !empty($networks[$pref1])) {
echo $phones[$pref] + $networks[$pref1];
}

Answer 5

If your code isn't going to be more complicated then what i see now
I would just change:
...
<option value="iPhone">Apple iPhone 4s</option>
...
<option value="Orange">Orange</option>
...
to
...
<option value="5">Apple iPhone 4s</option>
...
<option value="10">Orange</option>
...
And then loop all the values at the end
$total = 0;
foreach ($_POST as $key => $val) {
$total += $val;
}
echo $total;
That way you can change the amount of dropdowns