golang time.Now().Format with milliseconds without dot in string

[Vasiliy Tolstov]

Hi! I'm read several times godoc about the time package but have now
way to deal with it.
I need to output strings with format YYYYMMDDHHMMSSMILLISEC without
dot in string. But go able to output milliseconds only in case of .000


--
Vasiliy Tolstov,
e-mail: v.to...@selfip.ru

[Jake Montgomery]

Why not just remove the dot? You know where it is: https://play.golang.org/p/ZHqHTOeA7HQ

Perhaps there is a better way, but this seems to work.

[Vasiliy Tolstov]

вт, 14 июл. 2020 г. в 15:17, Jake Montgomery <jake...@gmail.com>:

>
> Why not just remove the dot? You know where it is: https://play.golang.org/p/ZHqHTOeA7HQ
> Perhaps there is a better way, but this seems to work.
>

Yes, thanks. My question mostly - why format time to some intermediate
string that needs to be preprocessed before usage =)
Format means that you get a needed sting and not that you must use
slice manipulation.

[Jake Montgomery]

I agree, it seems like an unfortunate oversight. You can do it without the slice tricks: https://play.golang.org/p/tNAPOcQqApN

It does take an additional Sprintf() though.

[Vasiliy Tolstov]

вт, 14 июл. 2020 г. в 18:39, Jake Montgomery <jake...@gmail.com>:

>
> I agree, it seems like an unfortunate oversight. You can do it without the slice tricks: https://play.golang.org/p/tNAPOcQqApN
> It does take an additional Sprintf() though.
>

Thanks, looks good. But i think for go devs adding additional format
that can be used to specify milli/micro/nano seconds will be easy.

[Justin Israel]

I asked the same question on reddit about a month ago, where I needed to match an existing timestamp format:

https://www.reddit.com/r/golang/comments/gr7hz9/string_formatting_a_timetime_with_custom/

Seems string formatting was the best option available to me.

 

[Vasiliy Tolstov]

пт, 17 июл. 2020 г. в 05:40, Justin Israel <justin...@gmail.com>:

Yes, this is bad case for stuff that works with many messages and
want to avoid additional memory allocations

[peterGo]

Vasiliy Tolstov,

"I need to output strings with format YYYYMMDDHHMMSSMILLISEC without dot in string. But Go able to output milliseconds only in case of .000" ... "that works with many messages and want to avoid additional memory allocations"

The Go standard library does not pretend to provide everything you might need. Sometimes you need to do some programming. For example,

    func formatMillisecond(t time.Time) string

    fmtms.go
    https://play.golang.org/p/dfackUTL9qw

    $ go run fmtms.go

    20091110230000.001
    20091110230000001

A specialized function is often faster that a generalized function.

    fmtms_test.go
    https://play.golang.org/p/wS7PqZjExDq

    $ go test fmtms_test.go fmtms.go -bench=. -benchmem

    BenchmarkFmtMs-4   11470974   101 ns/op   32 B/op   1 allocs/op
    BenchmarkNoDot-4    4385608   272 ns/op   64 B/op   2 allocs/op
    BenchmarkDot-4      5529204   215 ns/op   32 B/op   1 allocs/op

Peter