# Is there a way to test if something \`isexported()\`?
**URL:** https://discourse.julialang.org/t/is-there-a-way-to-test-if-something-isexported/8139
**Category:** General Usage
**Tags:** question
**Created:** [January 3, 2018, 11:19pm UTC](https://discourse.julialang.org/t/is-there-a-way-to-test-if-something-isexported/8139 "2018-01-03T23:19:17Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@djsegal](https://discourse.julialang.org/u/djsegal)
#### Post date: [January 3, 2018, 11:19pm UTC](https://discourse.julialang.org/t/is-there-a-way-to-test-if-something-isexported/8139/1 "2018-01-03T23:19:17Z")
Sometimes `isdefined` is a little too loose.
Is there a way to see if a variable is explicitly exported by a module?
* * *
Example:
```nohighlight
# src/FizzBuzz.jl
module FizzBuzz
export foo
foo() = println("hello")
bar() = println("world")
end
```
```nohighlight
# Julia REPL
> isdefined(FizzBuzz, :foo)
true
> isdefined(FizzBuzz, :bar)
true
> isexported(FizzBuzz, :foo)
true
> isexported(FizzBuzz, :bar)
false
```
---
### Author:  [@raminammour](https://discourse.julialang.org/u/raminammour)
#### Post date: [January 3, 2018, 11:41pm UTC](https://discourse.julialang.org/t/is-there-a-way-to-test-if-something-isexported/8139/2 "2018-01-03T23:41:39Z")
`Base.isexported` on `0.6` ?
---
### Author:  [@djsegal](https://discourse.julialang.org/u/djsegal)
#### Post date: [January 3, 2018, 11:44pm UTC](https://discourse.julialang.org/t/is-there-a-way-to-test-if-something-isexported/8139/3 "2018-01-03T23:44:22Z")
That’s exactly what I wanted. How did you find out about that? (it’s not in the docs)
---
### Author:  [@raminammour](https://discourse.julialang.org/u/raminammour)
#### Post date: [January 3, 2018, 11:50pm UTC](https://discourse.julialang.org/t/is-there-a-way-to-test-if-something-isexported/8139/4 "2018-01-03T23:50:10Z")
Just by accident :), I assumed that they must have it to define what to bring into the Main module after `using FizzBuzz`, so I looked in `Base` and `Core`.
```julia
julia> isdefined(Base,:isexported)
true
julia> Base.isexported(Base,:isexported)
false
```
---
### Author:  [@Liso](https://discourse.julialang.org/u/Liso)
#### Post date: [January 4, 2018, 10:53pm UTC](https://discourse.julialang.org/t/is-there-a-way-to-test-if-something-isexported/8139/5 "2018-01-04T22:53:05Z")
Maybe this is stupid idea:
```julia
julia> [i for i in names(Base, true) if contains(string(i), "exported")]
4-element Array{Symbol,1}:
Symbol("#is_exported_from_stdlib")
Symbol("#isexported")
:is_exported_from_stdlib
:isexported
```
But using undocumented features could be bad idea too…
---
### Author:  [@raminammour](https://discourse.julialang.org/u/raminammour)
#### Post date: [January 4, 2018, 11:18pm UTC](https://discourse.julialang.org/t/is-there-a-way-to-test-if-something-isexported/8139/6 "2018-01-04T23:18:29Z")
Here is an implementation using `names` which is documented:
```julia
isexported(m::Module,s::Symbol)=(s \in names(m,true)) && (s \in names(m))
```
(I could not get the `\in` tab to get the right symbol)
---
### Author:  [@Liso](https://discourse.julialang.org/u/Liso)
#### Post date: [January 5, 2018, 2:20am UTC](https://discourse.julialang.org/t/is-there-a-way-to-test-if-something-isexported/8139/7 "2018-01-05T02:20:03Z")
Implementation in Base is this:
```julia
isexported(m::Module, s::Symbol) = ccall(:jl_module_exports_p, Cint, (Any, Any), m, s) != 0
```
Sorry but your implementation doesn’t work. According to doc `names(m)` is subset of `names(m, true)` which makes part of your code redundant. Also exported deprecated symbols are ignored. See:
```julia
#Julia 0.7
julia> isexported(m::Module,s::Symbol)=(s ∈ names(m,true)) && (s ∈ names(m))
isexported (generic function with 1 method)
julia> isexported(Base, :zeta)
false
julia> Base.isexported(Base, :zeta)
true
```
---
### Author:  [@raminammour](https://discourse.julialang.org/u/raminammour)
#### Post date: [January 5, 2018, 3:26pm UTC](https://discourse.julialang.org/t/is-there-a-way-to-test-if-something-isexported/8139/8 "2018-01-05T15:26:44Z")
You are right about the `names` so the the two are redundant (I misunderstood `names`, I wanted something that almost can tell if it is defined/undefined, and then decide if it is exported).
Now, weirdly on `0.6`:
```julia
julia> isexported(Base,:zeta)
true
julia> Base.isexported(Base,:zeta)
true
```
I don’t have `0.7` but I thought that special functions where taken out from `Base` in `0.7`.
---
### Author:  [@Liso](https://discourse.julialang.org/u/Liso)
#### Post date: [January 5, 2018, 5:02pm UTC](https://discourse.julialang.org/t/is-there-a-way-to-test-if-something-isexported/8139/9 "2018-01-05T17:02:49Z")
Maybe I am wrong. I tried to simulate deprecated symbol. And zeta on 0.6 is working without deprecation message:
```julia
julia> zeta(0)
-0.5
```
and on 0.7 deprecation is faked up:
```julia
julia> zeta(0)
ERROR: Base.zeta has been moved to the package SpecialFunctions.jl.
Run `Pkg.add("SpecialFunctions")` to install it, restart Julia,
and then run `using SpecialFunctions` to load it.
Stacktrace:
[1] error(::Function, ::String, ::String, ::String, ::String, ::String, ::String, ::String, ::String, ::String) at ./error.jl:42
[2] #zeta#852(::Base.Iterators.IndexValue{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}, ::Function, ::Int64, ::Vararg{Int64,N} where N) at ./deprecated.jl:142
[3] zeta(::Int64, ::Vararg{Int64,N} where N) at ./deprecated.jl:142
[4] top-level scope
```
So I tried to find really deprecated symbol on 0.6:
```julia
julia> ipermutedims([1 2;3 4], (2,1))
┌ Warning: `ipermutedims(A::AbstractArray, p)` is deprecated, use `permutedims(A, invperm(p))` instead.
│ caller = top-level scope
└ @ Core :0
2×2 Array{Int64,2}:
1 3
2 4
julia> Base.isexported(Base, :ipermutedims)
true
```
but:
```julia
julia> :ipermutedims in names(Base)
true
```
So it seems I don’t understand what is doc saying:
```julia
help?> names
```
Get an array of the names exported by a Module, **excluding deprecated names.**