# Why add periods after functions?

**URL:** <https://discourse.julialang.org/t/why-add-periods-after-functions/27255>\
**Category:** New to Julia\
**Created:** [August 7, 2019, 7:13am UTC](https://discourse.julialang.org/t/why-add-periods-after-functions/27255 "2019-08-07T07:13:13Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![MuadhF](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/muadhf/32/20389_2.png) [@MuadhF](https://discourse.julialang.org/u/MuadhF)\
**Post date:** [August 7, 2019, 7:13am UTC](https://discourse.julialang.org/t/why-add-periods-after-functions/27255/1 "2019-08-07T07:13:13Z")

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Hi,

I’m relatively new to Julia, and I have been going through a lot of manuals and stuff. I was wondering, why would there be a period after some functions, and sometimes there isn’t? For example, I’ve seen

`DataFrame.(...)` and at other times `DataFrame(...)`

or

`insert!.(...)` as well as `insert.(...)`.

What is the significance of adding a period in such cases? Or is there no general rule and each one has a different reason?

Thanks!

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**Author:** ![jbrea](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jbrea/32/3879_2.png) [@jbrea](https://discourse.julialang.org/u/jbrea)\
**Post date:** [August 7, 2019, 7:15am UTC](https://discourse.julialang.org/t/why-add-periods-after-functions/27255/2 "2019-08-07T07:15:20Z")

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Please have a look [here](https://docs.julialang.org/en/v1/base/arrays/#Broadcast-and-vectorization-1) and [here](https://docs.julialang.org/en/v1/manual/functions/#man-vectorized-1).

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**Author:** ![MuadhF](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/muadhf/32/20389_2.png) [@MuadhF](https://discourse.julialang.org/u/MuadhF)\
**Post date:** [August 7, 2019, 7:28am UTC](https://discourse.julialang.org/t/why-add-periods-after-functions/27255/3 "2019-08-07T07:28:24Z")

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Thanks, makes sense now!