wierd if statement about pure-bash-bible HOT 1 OPEN

For the love of Bash and own safety, please do quote variables; The extension is to be .bash, not .sh, or go without any. Of course not forget to start a Bash script with this to make it run right:

#!/usr/bin/env bash

Anyways, the 1st shall've "${1:-""}" to be the same, no parsing errors then. Why? if ; then must have something between if and ; and you may just put safe : or simple true to bypass it, though it is sort of pointless in this case and should be like if [[ -n "${1:-""}" ]]; then if want to just make sure something is in "${1:-""}". On echo, please prefer to use more predictable safe printf instead or upgrade echo by this simple function at the start of a script:

echo() { printf -- '%s\n' "${*:-""}"; }

from pure-bash-bible.