CODEWITHSUNDEEP
elixirecto
Torito
Torito

Reputation: 315

multiplying Decimal and Integer throws "bad argument in arithmetic expression"

In my project I have to calculate a total price of a product by multiplying a price in Decimal to quantity in Integer. When I do so, I'm getting an exception "bad argument in arithmetic expression". How can solve that? I wouldn't want to lose data if I have to round a result.

Upvotes: 3

Views: 2642

Answers (1)

Dogbert
Dogbert

Reputation: 222348

Elixir does not allow operator overloading, so the decimal package cannot make the * operator work on Decimal. The package does provide a function Decimal.mult/2 to multiply Decimal values, which accepts 2 Decimal values, which you can use. You need to first convert the integer to a Decimal using Decimal.new/1 and then use Decimal.mult/2:

iex(1)> d = Decimal.new("0.11111111111111111111")
#Decimal<0.11111111111111111111>
iex(2)> Decimal.mult(d, Decimal.new(3))
#Decimal<0.33333333333333333333>
iex(3)> 0.11111111111111111111 * 3 # This loses precision because Elixir's native floats are 64 bit IEEE floats
0.3333333333333333

Upvotes: 8

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