How to return multiple arrays with function

Question

I wrote a function which returns an array:

create(){
   my_list=("a" "b" "c")
   echo "${my_list[@]}"
}

result=$(create)
for var in result
do
    echo $var
done

Now, I'd like to extend it in order to return multiple arrays. For example, I'd like to write something like that:

create(){
    my1=("1" "2")
    my2=("3","4")
    my3=("5","6")
     echo "${my1[@]} ${my3[@]} ${my3[@]}"
}

and I'd like to get each of the returned arrays:

 res1= ...
 res2= ...
 res3= ...

Anyone could suggest me a solution? Thanks

Why can't you just maintain a variable in global context, returning arrays is not the best of ways to design your code — Inian, Apr 26 '17 at 11:32
If you can let us know your requirement, there are sure better ways to do this — Inian, Apr 26 '17 at 11:33
Technically, you can't even return a *single* array; you can *output* the *elements* of one or more arrays. — chepner, Apr 26 '17 at 11:39
Try setting `my_list=("a b" "c d" "e f")` inside `create` and see what happens. — chepner, Apr 26 '17 at 11:49
@Inian I have a file to read. Each line has two values and I want to store the first value of each line in the first array, the second value of each line in the second array. I want to do this with a function. — Fab, Apr 26 '17 at 11:51
See [How to return an array in bash without using globals?](http://stackoverflow.com/q/10582763/4154375). — pjh, Apr 26 '17 at 18:21

score 1 · Answer 1 · answered Apr 26 '17 at 11:53

You need to read with a while loop.

while read -r val1 val2; do
    arr1+=("$val1")
    arr2+=("$val2")
done < file.txt

There is no such thing as an array value in bash; you cannot use arrays the way you are attempting in your question. Consider this result:

create(){
   my_list=("a 1" "b 2" "c 3")
   echo "${my_list[@]}"
}

result=$(create)
for var in $result
do
    echo $var
done

This produces

a
1
b
2
c
3

not

a 1
b 2
c 3

1 Answers1