# Question on RefValue

**URL:** <https://discourse.julialang.org/t/question-on-refvalue/53498>\
**Category:** General Usage\
**Created:** [January 17, 2021, 8:12pm UTC](https://discourse.julialang.org/t/question-on-refvalue/53498 "2021-01-17T20:12:09Z")\
**Posts on this page:** 1\
**Showing post:** 12

<div class="post-metadata">

**Author:** ![Skoffer](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/skoffer/32/378_2.png) [@Skoffer](https://discourse.julialang.org/u/Skoffer)\
**Post date:** [January 18, 2021, 2:38pm UTC](https://discourse.julialang.org/t/question-on-refvalue/53498/12 "2021-01-18T14:38:12Z")

</div>

It is even better than list defined by someone, you can use Julia functions to construct it!

According to [View all functions exported in a package](https://discourse.julialang.org/t/view-all-functions-exported-in-a-package/42794)

```julia
julia> names(Base)
915-element Vector{Symbol}:
 :!
 :!=
 :!==
 ⋮

julia> names(Base, all = true)
5391-element Vector{Symbol}:
 :!
 :!=
 :!==
 ⋮

```

And for each exported symbol you can read documentation with the help of `?`

```julia
julia> ? # you need to press question mark to switch to help mode
help?> !
search: ! != !== sum! put! pop! map! get! any! all! take! sort! read! push! prod! kron! fill! copy! conj! union! popat! merge! empty! count! clamp! unique! splice! resize! insert! filter!

  !(x)

  Boolean not. Implements three-valued logic (https://en.wikipedia.org/wiki/Three-valued_logic), returning missing if x is missing.

```

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_[View the full topic](https://discourse.julialang.org/t/question-on-refvalue/53498)._