Subtraction in php! - need a bit of help (it should be simple!)

[mr_c]

hey guys, i'm new to the forum and to php. I'm trying to subtract two variables like this but it just doesn't want to work, i'm working on a shopping cart software that uses php and this is the code that i need to subtract:

{convertPrice price=$product->getPriceWithoutReduct()-$product->getPrice()}

what is so confusing to me is that the next code (below this paragraph) shows both variables come up with their values in the browser, for example, in the browser this comes up: £10 £9, and all i want is for the variable values to subtract themselves so it comes out as £1

{convertPrice price=$product->getPriceWithoutReduct()}{convertPrice price=$product->getPrice()}

and if i try this:

{convertPrice price=$product->getPriceWithoutReduct()-2}

or

{convertPrice price=$product->getPrice()-2}

the values do get subtracted by 2!!

it only breaks when i try to subtract the vars with each other!

is there any way i can subtract those two variables?

thanks in advance

[johanafm]

Using what, smarty? If so there are various ways to deal with this.

Separate variable assignment

{assign var="val1" value=$product->getPriceWithoutReduct()}
{assign var="val2" value=$product->getPrice()}
{* I know you can use it like this now *}
{$val1-$val2}
{* And that means this will probably also work *}
{convertPrice price=$val1-$val2}

modifier

// modifier.subtract.php
function smarty_modifier_subtract($first, $second) {
	return $first - $second;
}

// in template
{convertPrice price=$product->getPriceWithoutReduct()|subtract:$product->getPrice()}

or simply modify convertPrice

// in template
{convertPrice price=$product->getPriceWithoutReduct() sub=$product->getPriceWithoutReduct()}

// in function.convertPrice.php, do something along the lines of...
function smarty.convertPrice.php($params, &$smarty) {
	$price = isset($params['price']) ? $params['price'] : 0;
	$sub = isset($params['sub']) ? $params['price'] : 0;
	$price -= $sub;

// rest of the code...
}

[mr_c]

Yeessssssssssssssssssssssssssssssssssssssssssssssssss 🙂

I assigned the variables and it worked perfect! (first suggestion)

10/10 mate, thank you very very much, i have much to learn if i can't solve simple problems like this heh. Thanks again!