How can I get unique values from an array in Bash?

Question

I\'ve got almost the same question as here.

I have an array which contains aa ab aa ac aa ad, etc. Now I want to select all unique elements from this ar

Answer 1

If you want a solution that only uses bash internals, you can set the values as keys in an associative array, and then extract the keys:

declare -A uniqs
list=(foo bar bar "bar none")
for f in "${list[@]}"; do 
  uniqs["${f}"]=""
done

for thing in "${!uniqs[@]}"; do
  echo "${thing}"
done

This will output

bar
foo
bar none