PHP货币换算舍入错误

Question

I have a database which stores currency amounts in GBPs (to two decimal places). Occasionally we get orders in in USD. These are converted prior to storage using an exchange rate of 1.51. The problem is when these figures are retrieved and converted back to the original currency I am encountering small rounding errors. For example...

$amount = 100 ///figure in USD
$gbpAmount = number_format((float)($amount/1.51), 2, '.', ''); //// gives GBP figure of 66.23

////Store this in dB then retrive////

$usdAmount = number_format((float)($gbpAmount*1.51), 2, '.', ''); //// gives USD figure of 100.01

Any ideas on how I can resolve this problem?

Many thanks

Answer 1

I once faced the same issue. My values where stored in a table.

So instead of saving 2 decimal, I saved 6 and shows only 2 in the client side