Thanks! It's not lost, though. It shows up with the %g form.
Knowing about %g, my issue is not extant, but others might hit it. I'm relatively new to floating point issues, and I saw numbers showing up as integers, and it took a while to sort out what was going on, is all. As the behavior matches "c", I would suggest at minimum making the documentation clearer. https://go.dev/play/p/WBlf3jltimr On Monday, October 10, 2022 at 10:27:00 AM UTC-7 Brian Candler wrote: > Whilst Go handles constants with arbitrary precision AFAIK, precision is > lost once values are assigned to a float64 variable (or passed as an > argument to a function). There are only 53 bits of precision in the > "mantissa". > > For more info, you might find this helpful: > https://0.30000000000000004.com/ > > On Monday, 10 October 2022 at 17:48:56 UTC+1 dante.ca...@gmail.com wrote: > >> Hi, >> >> I'm wondering what folks think about the behavior of %f and precision. >> >> The go fmt documentation states: >> > For floating-point values, width sets the minimum width of the field >> and precision sets the number of places after the decimal, >> >> What I discovered is there is rounding going on in %f as shown below. >> >> https://go.dev/play/p/23AfRtwOqcD >> >> I found this behavior as I'm converting floats to integers, and was >> testing fine regions between digits, and experienced the behavior. I >> didn't expect it. >> >> I expected the behavior of printing "n" characters of a string. However, >> I note that "c" behaves the same way: >> >> $ cat math.c >> #include<stdio.h> >> int main(int argc, char *argv[]) { >> printf("%0.3f\n", 0.9999999999); >> } >> $ ./math >> 1.000 >> $ >> > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/4a15ac2c-e30d-4d6e-be8f-251996fb01cen%40googlegroups.com.
