获取小数点后的位数

Question

What's the idiomatic way to get the number of digits after the decimal for a currency? More specifically, based on the Wikipedia page for ISO 4217, I want the following mapping between currency codes / number of places after the decimal:

• USD: 2
• JPY: 0
• EUR: 2

Is there a library which would get this information for me?

Answer 1

I'd recommend checking out the x/text/currency library.

It has functionality for fetching how many decimals ought to be used for a currency in standard, cash, or accounting contexts. For example:

currencyNames := []string{"USD", "JPY", "EUR"}
for _, currencyName := range currencyNames {
        isoCurrency := currency.MustParseISO(currencyName)
        scale , _ := currency.Standard.Rounding(isoCurrency)
        fmt.Printf("%s: %d
", currencyName, scale)
}

Gives:

USD: 2
JPY: 0
EUR: 2

Depending on what you're hoping to do with that information, some of the formatting functions in that library may be even closer to what your end goal is.

One caveat though, as noted on the linked documentation page:

NOTE: the formatting functionality is currently under development and may change without notice.