LWC lightning-formatted-number

I suspect a bug in the lightning-formatted-number Lightning Web Component. Can anyone confirm, or have I misunderstood?

I have this in a LWC:

``````<lightning-formatted-number value="123.456" maximum-fraction-digits="2" maximum-significant-digits="8">
</lightning-formatted-number>
<br/>
<lightning-formatted-number value="123.456" maximum-fraction-digits="3" maximum-significant-digits="5">
</lightning-formatted-number>
``````

It displays as:

``````123.456
123.46
``````

I would have expected the first number so be displayed is 123.46 because of `maximum-fraction-digits="2"` but, as you see, all 3 decimal places are shown. (Assuming 'fraction digits' is some strange Salesforcey way of saying 'decimal places')

The 2nd number displays as I would expect, because `maximum-significant-digits="5"`

So, it seems to me that `maximum-fraction-digits` does not work, but `maximum-significant-digits` does. Am I right in believing this to be a bug & if so, how can I work around?

• There is a difference between fraction digits and significant digits according to maths. If you want to fix the number of digits with trailing zeros then use the min fraction digits. or if you want to fix the number of fraction digits with rounding then use max fraction digits. Significant digits consider numbers before decimal point as well whereas fraction considers only after decimal point. Aug 30, 2021 at 14:55
• @RahulGawale yes, I understand. However, for the first number, maximum-fraction-digits=2 yet the number still displays 3 d.p. That is the problem. Aug 30, 2021 at 15:16
• I think you need to use either of them as significant digit property overwrites the fraction digits. because significant digits also consider the numbers before the decimal point, for example, -> if you mention a significant digit as 8 then fraction digits will not show when the total number of digits to left of the decimal point is greater or equal to 8, so `12345678.456` => `12345678` even if min fraction digits are mentioned as 3. Aug 30, 2021 at 15:30
• @RahulGawale again, I understand, but in my example, `123.456` has 6 significant digits. Setting `maximum-significant-digits` to 5 correctly shows the number as `123.46` but but setting `maximum-fraction-digits` to 2 should, I think, show as `123.46` but actually shows as `123.456` Aug 30, 2021 at 15:36