What will be the output if there are no common elements between c and z?

If there are no common elements between arrays c and z, the output of the script will be:

Common elements among a, b, and c: 

This means that the array j, which stores the common elements, will remain empty, and nothing will be displayed after the colon. If you want to indicate that there are no common elements, you could modify the script to include a message like:

if [ ${#j[@]} -eq 0 ]; then
  echo "No common elements among a, b, and c."
else
  echo "Common elements among a, b, and c: ${j[@]}"
fi

This way, it will clearly state when there are no common elements. Let me know if you need further assistance!