Addition And Subtraction Issue

[dreampho]

Hi. I have a simple math line, and I cant work out why its subtracting the $extra_cost variable, where as it should be adding it?

 

<?php $deposit = substr("300"); $full_price = "1000"; $extra_cost = "10"; $remaining_balance = $deposit - $full_price + $extra_cost; $remaining_balance = substr("$remaining_balance",1); ?>

 

Thank you

[Barand]

Lost the return key from your keyboard?

[Andy123]

Try to use parenthesis in your calculation. Also, I am not sure why you are using substr()? I would also not be using the numbers as a string, but int instead, like this:

 

$deposit = 300;

[JD*]

Are you looking to have a negative number return? If not, you may want to change the order of your equation.

 

Here it is cleaned up a bit. Also, per Andy123, you really don't need the substring calls, and you should have your numbers as numbers, without quotes:

 

$deposit = 300;
$full_price = 1000;
$extra_cost = 10;
$remaining_balance = ($full_price - $deposit) + $extra_cost;
echo $remaining_balance;