php - How to transform the Magento order price in cents? -

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i have nasty bug payments in magento, paybox , soap web services, idea following:

  1. payment made in cents $36.37 = 3637cents (paybox - api)

  2. what trying transform order price in cents in following way:

    $cents = $order->getbasegrandtotal() * 100;

  3. also have web service soap (strict types) respond $cents amount concerts (int), magic happens converted amount not expected one, converted result less cent, in case 3736.

    $prices = array(39.8699, 12.3299, 11.3211);  foreach ($prices $price) {     $stuff = round($price, 2) * 100;      echo $stuff . php_eol; }  echo "after int conversion" . php_eol;  foreach ($prices $price) {     $stuff = (int) (round($price, 2) * 100);      echo $stuff . php_eol; }

the result following:

3987 1233 1132 after int conversion 3986 1233 1132

question there way fix bug, seems php bug ?

your algorithm summarises this:

  1. $price = 39.8699; // 39.869900000000001228
  2. round($price, 2) * 100; // 3986.9999999999995453
  3. (int)3986.9999999999995453; // 3986

you're rounding everywhere, except in last step, (int) casting truncates. rounding more appropriate:

round($price * 100)

said that, root problem computers use binary logic , store numbers base 2, while humans use fuzzy logic , prefer base 10. there isn't problem "small" integers because there's 1 1 correspondence storing arbitrary base 10 floating points numbers in fixed-sized base 2 representation approximation. classical example 1.1 has 2 digits in base 10 periodic in base 2:

1.0001100110011001100110011001100110011001100110011001100110011001101...

that's why common advice includes using exact data types when available (decimal in relational database, integers in client code).


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