Your answer won't work, for two reasons:
$array1 just expands to the first element of array1. (At least, in my installed version of Bash that's how it works. That doesn't seem to be a documented behavior, so it may be a version-dependent quirk.)- After the first element gets added to
result, result will then contain a space, so the next run of result=$result" "$item1 will misbehave horribly. (Instead of appending to result, it will run the command consisting of the first two items, with the environment variable result being set to the empty string.) Correction: Turns out, I was wrong about this one: word-splitting doesn't take place inside assignments. (See comments below.)
What you want is this:
result=()
for item1 in "${array1[@]}"; do
for item2 in "${array2[@]}"; do
if [[ $item1 = $item2 ]]; then
result+=("$item1")
fi
done
done
