Question

I need to convert a decimal value into something like

0.3 = USDC000000000030

The code i wrote is as below.

   transactionAmount = String.Format("USDC{0}", ((int)(amount*100)).ToString("D12"));

However, it is working for some values perfectly like the example given above. For other some values it is conversion is wrong for example

0.9 = USDC000000000089

1 = USDC000000000099

1.1 USDC000000000109

Any idea why is it happening so?

Thanks in advance

Answer 1

You’re probably using double, which for financial values is a huge mistake.

Use decimal instead, and wash your troubles away.

To wit:

decimal amount = 0.3m;
string s = String.Format("USDC{0:000000000000}", 100 * amount);
Console.WriteLine(s);

Output:

USDC000000000030

Note that the language specification states:

The decimal type is a 128-bit data type suitable for financial and monetary calculations.