Bash pairwise array expansion

Question

I have two arrays of same lengths like following:

arr1[1]=2
arr1[2]=5

arr2[1]=x
arr2[2]=y

I am trying to create a string like " 2 x 5 y ".

Since the length of the arrays can be a variable, is there any way to do this without using a loop and string concatenation (like parameter expansion or something) ?

Answer 1

You can use paste with process substitution :

arr1[1]=2
arr1[2]=5

arr2[1]=x
arr2[2]=y

s=$(paste <(printf "%s\n" "${arr1[@]}") <(printf "%s\n" "${arr2[@]}") |
    tr '[[:space:]]' ' ')
echo "$s"
2 x 5 y