bash: iterate, and regex example

iterateregex_example.sh

#!/bin/sh
set -o errexit

foo="a 1a b c d e"
bar="a b d e f g"

for x in $bar
do
	if ! [[ "$foo" =~ (^|[[:blank:]])$x([[:blank:]]|$) ]]; then
		echo $x
	fi
done