PHP; sum of returned numbers from eBay API is invalid

Question

I seem to be having an issue with PHP rounding (sort of) numbers by default, I am calling the eBay API and getting back the price of an item and the postage. I need to add these two numbers before entering them into my database, the issue seems to be when I add the two numbers up they come back with a strange value:

shipping = 5.95
item price = 18.55

If I add the two up I get a result of 23.

$ship = $item->shippingInfo->shippingServiceCost;
$price = $item->sellingStatus->currentPrice;
$sell = ($ship + $price);

Do I need to tell php the returned value is a number?

Answer 1

Make sure both of your values are actually integers or floats, instead of strings. Summing strings to eachother could result in strange behavior.

Try this:

$ship = (float) $item->shippingInfo->shippingServiceCost;
$price = (float) $item->sellingStatus->currentPrice;
$sell = ($ship + $price);

Now $sell should consist of a float. You can use (float) to cast the variable to a floating variable.

Answer 2

Take a look at typecasting in general, as is quite important in a variety of scenarios for you as a PHP developer.

Answer 3

The problem is not the $ship is a string with 5.95 .. that would be properly converted to float but I think it is .. 5,95 and that would be converted to 5

<?php
$ship = "5,95";
$price = "18,55";
$sell = ($ship + $price);
echo "$sell = ($ship + $price)";

?>

output:

23 = (5,95 + 18,55)

convert:

<?php
$ship = (float) "5,95";
$price = (float) "18,55";
$sell = ($ship + $price);
echo "$sell = ($ship + $price)";
?>

output:

23 = (5 + 18)

Use:

$ship = str_replace(',','.',$ship);
$price = str_replace(',','.',$price); 

And it should work!