How to increase % depending on id?

Question

PHP

Good day to all!
Please help with the issue of increasing the price for a specific id. When you run the php file, an XML file is generated and data is displayed for each product.
We need to make sure that a percentage is added to each category and a new value is displayed.

There is the following data:
$price = CPrice::GetBasePrice($arItem['ID']); // price is pulled from the database.
$arBlocks = array(45, 44, 2, 43, 8, 9, 99); // numbers act as category ids.
foreach ($arBlocks as $IBLOCK_ID)

There are categories of goods and for each of the categories a certain percentage must be added to the amount. I understand that we should make a new variable for them.

$newPrice = $price;

switch ($IBLOCK_ID) {

case 45:
(int)$price = 1.10 * (int)$newPrice;
break;

case 44:
(int)$price = 1.20 * (int)$newPrice;
break;

case 2:
(int)$price = 1.30 * (int)$newPrice;
break;

case 43:
(int)$price = 1.25 * (int)$newPrice;
break;

case 8:
(int)$price = 1.30* (int)$newPrice;
break;

case 9:
(int)$price = 1.20 * (int)$newPrice;
break;

case 99:
(int)$price = 1.10 * (int)$newPrice;
break;
}

write_to_file($file, ' '.$price['PRICE'].'');

Tried the option above, doesn't work. Please advise what can be done in such a situation?
Thank you!

Answer 1

foreach ($arBlocks as $IBLOCK_ID) {
  $multiplier = getPriceMultiplierByBlock($IBLOCK_ID);
  $newPrice = $price * $multiplier;
  // сохраняйте
}

function getPriceMultiplierByBlock($blockId) {
  $multipliers = [
    2 => 1.30,
    8 => 1.30,
    9 => 1.20,
    43 => 1.25,
    44 => 1.20,
    45 => 1.10,
    99 => 1.10,
    // ...
  ];
  return isset($multipliers[$blockId])
    ? $multipliers[$blockId]
    : 1; // если множитель не указан - единица
}