# API to retrieve the docstring of a function
**URL:** https://discourse.julialang.org/t/api-to-retrieve-the-docstring-of-a-function/10722
**Category:** General Usage
**Created:** [May 5, 2018, 8:15am UTC](https://discourse.julialang.org/t/api-to-retrieve-the-docstring-of-a-function/10722 "2018-05-05T08:15:20Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@essenciary](https://discourse.julialang.org/u/essenciary)
#### Post date: [May 5, 2018, 8:15am UTC](https://discourse.julialang.org/t/api-to-retrieve-the-docstring-of-a-function/10722/1 "2018-05-05T08:15:20Z")
I would like to programmatically get the docstring associated to a function – is that possible?
On a related note, how can we apply reflection and introspection techniques to functions? In Julia functions are first-class, but they don’t seem to behave like standard objects (as least the way one might expect by comparison with other languages). What kind of beast is this? 👹
```julia
julia> g = (x) -> 2x
(::#23) (generic function with 1 method)
julia> typeof(g)
##23#24
julia> isa(g, Function)
true
julia> f = Function()
ERROR: MethodError: no constructors have been defined for Function
julia> fieldnames(typeof(g))
0-element Array{Symbol,1}
julia> methods(g)
# 1 method for generic function "(::#23)":
(::##23#24)(x) in Main at REPL[8]:1
julia> methods(Function)
# 1 method for generic function "(::Type)":
(::Type{T})(arg) where T in Base at sysimg.jl:77
```
---
### Author:  [@jonathanBieler](https://discourse.julialang.org/u/jonathanBieler)
#### Post date: [May 5, 2018, 9:04am UTC](https://discourse.julialang.org/t/api-to-retrieve-the-docstring-of-a-function/10722/2 "2018-05-05T09:04:05Z")
```julia
Base.doc(Base.Docs.Binding(Base.Docs.current_module(),:rand))
```
You can find this using `macroexpand( :(@doc rand) )`.
Otherwise you often want to look at methods instead of functions:
```julia
julia> m = collect(methods(rand))[1]
rand(rd::RandomDevice, ::Type{T}) where T<:Union{Bool, Int128, Int16, Int32, Int
64, Int8, UInt128, UInt16, UInt32, UInt64, UInt8} in Base.Random at random.jl:40
julia> fieldnames(m)
19-element Array{Symbol,1}:
:name
:module
:file
:line
:sig
:min_world
:ambig
:specializations
:sparam_syms
:source
:unspecialized
:generator
:roots
:invokes
:nargs
:called
:isva
:isstaged
:pure
```
---
### Author:  [@essenciary](https://discourse.julialang.org/u/essenciary)
#### Post date: [May 5, 2018, 10:12am UTC](https://discourse.julialang.org/t/api-to-retrieve-the-docstring-of-a-function/10722/3 "2018-05-05T10:12:39Z")
Excellent, thank you!