Question

I have an array made of:

old_array=("color" "red" "shape" "circle" "vote" "10")

(alternating key/values)

I need to build a new_array so that:

echo $new_array[color]
red

echo $new_array[shape]
circle

and so on.

Answer 1

You need bash’s associative arrays.

First, declare the variable as an Associative Array with declare -A:

declare -A new_array

Then set values in the array like you would do with regular arrays:

new_array[color]="red"

---

You can convert your old_array to new_array like this:

old_array=("color" "red" "shape" "circle" "vote" "10")
declare -A new_array
for (( i = 0; i < ${#old_array[*]}; i += 2 )); do
    key=${old_array[i]}
    value=${old_array[i+1]}
    new_array[$key]=$value
done

You can also write new_array directly:

declare -A new_array=([color]=red [shape]=circle [vote]=10)