Question

I have two arrays A and B. How do I combine them into a new array C, which is their Cartesian product? For example, given:

A=( 0 1 )
B=( 1 2 )

Desired output:

C=( 0:1 0:2 1:1 1:2 )

Answer 1

Since Bash supports sparse arrays, it’s better to iterate over the array than to use an index based on the size.

a=(0 1); b=(2 3)
i=0
for z in ${a[@]}
do
    for y in ${b[@]}
    do
        c[i++]="$z:$y"
    done
done
declare -p c   # dump the array

Outputs:

declare -a c='([0]="0:2" [1]="0:3" [2]="1:2" [3]="1:3")'