# Make function accept an array of strings and return an array of strings

**URL:** <https://discourse.julialang.org/t/make-function-accept-an-array-of-strings-and-return-an-array-of-strings/57473>\
**Category:** New to Julia\
**Tags:** nlp\
**Created:** [March 18, 2021, 1:21pm UTC](https://discourse.julialang.org/t/make-function-accept-an-array-of-strings-and-return-an-array-of-strings/57473 "2021-03-18T13:21:18Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![sonicrules1234](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/sonicrules1234/32/22938_2.png) [@sonicrules1234](https://discourse.julialang.org/u/sonicrules1234)\
**Post date:** [March 18, 2021, 1:21pm UTC](https://discourse.julialang.org/t/make-function-accept-an-array-of-strings-and-return-an-array-of-strings/57473/1 "2021-03-18T13:21:18Z")

</div>

I’m working on a google translate package, and I’ve got the translating part, but I want a function that will do a batch translate.

```julia
function batchtranslate(inputstrings::Array{String,1}, lang_tgt="auto"::String, lang_src="auto"::String)::Array{String}
    returnparts = Array(String)
    for part in inputstrings
        append!(returnparts, translate(part))
    end
    return returnparts
end
end

```

I do:

```julia
batchtranslate(["Hello.", "What is your name?"], "ja")

```

I keep getting errors no matter how I change Array{String} around. When I leave typing out of it, it seems to iterate through each character rather than each element in the input array.

---

<div class="post-metadata">

**Author:** ![pixel27](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pixel27/32/8902_2.png) [@pixel27](https://discourse.julialang.org/u/pixel27)\
**Post date:** [March 18, 2021, 1:26pm UTC](https://discourse.julialang.org/t/make-function-accept-an-array-of-strings-and-return-an-array-of-strings/57473/2 "2021-03-18T13:26:26Z")

</div>

I use `Vector` because it’s a little clearer. The big thing appears to be `returnparts`. I’m not sure what type that was getting defined as, but it wasn’t what you wanted.

```julia
function batchtranslate(inputstrings::Vector{String}, lang_tgt="auto"::String, lang_src="auto"::String)::Vector{String}
    returnparts = Vector{String}()
    for part in inputstrings
        append!(returnparts, translate(part))
    end
    return returnparts
end

```

---

<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:** [March 18, 2021, 1:27pm UTC](https://discourse.julialang.org/t/make-function-accept-an-array-of-strings-and-return-an-array-of-strings/57473/3 "2021-03-18T13:27:03Z")

</div>

Assuming that `lang_tgt` and `lang_src` are part of the `translate` api, you can use broadcasting

```julia
batchtranslate(inputstrings, lang_tgt = "auto", lang_src = "auto") = translate.(inputstrings, lang_tgt, lang_src)

```

As a side note, do not annotate so heavily.

---

<div class="post-metadata">

**Author:** ![sonicrules1234](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/sonicrules1234/32/22938_2.png) [@sonicrules1234](https://discourse.julialang.org/u/sonicrules1234)\
**Post date:** [March 18, 2021, 1:33pm UTC](https://discourse.julialang.org/t/make-function-accept-an-array-of-strings-and-return-an-array-of-strings/57473/4 "2021-03-18T13:33:23Z")

</div>

I tried your code, and it gave me:

```julia
julia> a = GoogleTrans.batchtranslate(["Hello. My name is Westly.", "What is your name?"], "ja")
ERROR: MethodError: Cannot `convert` an object of type Char to an object of type String
Closest candidates are:
  convert(::Type{T}, ::T) where T<:AbstractString at strings/basic.jl:229
  convert(::Type{T}, ::AbstractString) where T<:AbstractString at strings/basic.jl:230
  convert(::Type{T}, ::T) where T at essentials.jl:171
Stacktrace:
 [1] setindex!(::Array{String,1}, ::Char, ::Int64) at ./array.jl:847
 [2] _append!(::Array{String,1}, ::Base.HasLength, ::String) at ./array.jl:989
 [3] append!(::Array{String,1}, ::String) at ./array.jl:981
 [4] batchtranslate(::Array{String,1}, ::String, ::String) at /home/westly/google_trans_new/googletrans.jl:38
 [5] batchtranslate(::Array{String,1}, ::String) at /home/westly/google_trans_new/googletrans.jl:36
 [6] top-level scope at REPL[2]:1

```

As for Skoffer’s code, it worked, but I’m also thinking about using multiple dispatch to add it to the translate function instead of having a separate function for batch translation.

Any ideas on how to do that?

---

<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:** [March 18, 2021, 1:52pm UTC](https://discourse.julialang.org/t/make-function-accept-an-array-of-strings-and-return-an-array-of-strings/57473/5 "2021-03-18T13:52:23Z")

</div>

Well, since broadcasting is a first-class citizen in Julia, the best choice is to do nothing. If the user wants to translate vector of strings, he can apply broadcast and be happy about it.

But, still, you can do something like this

```julia
translate(inputstrings::AbstractVector{S}, lang_tgt = "auto", lang_src = "auto") where {S <: AbstractString} = translate.(inputstrings, lang_tgt, lang_src)

```

As a side effect, this function can translate nested expressions like `[["Hello", "my"], ["name is", "Alexandrou Panagouli"]]`

---

<div class="post-metadata">

**Author:** ![sonicrules1234](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/sonicrules1234/32/22938_2.png) [@sonicrules1234](https://discourse.julialang.org/u/sonicrules1234)\
**Post date:** [March 18, 2021, 1:56pm UTC](https://discourse.julialang.org/t/make-function-accept-an-array-of-strings-and-return-an-array-of-strings/57473/7 "2021-03-18T13:56:47Z")

</div>

Thanks, that worked.