Removing duplicates on a variable without sorting

Question

I have a variable that contains the following space separated entries.

variable=\"apple lemon papaya avocado lemon grapes papaya apple avocado mango banana\"         


        

Answer 1

This pipeline version works by preserving the original order:

variable=$(echo "$variable" | tr ' ' '\n' | nl | sort -u -k2 | sort -n | cut -f2-)