$ printf "this is a test"		#this is a test
$ printf 'this' 'is' 'a' 'test'		#missing format character

$ var="this is a test"
$ printf %s $var			#thisisatest ## all in one just like printf %s this is a test
$ printf %s "$var"			#this is a test ## var is a whole string input

printf "My name is \"%s\".\nIt's a pleasure to meet you." "John"
printf "%s\n" "hello printf" "in" "bash script" # format string will apply to each argument.

now="$(date)" #command substution
$ printf "Current date and time %s\n" "$now"
$ printf "today is %s" "`date`"

header="\n %-10s %8s %10s %11s\n"
printf "$header" "ITEM NAME" "ITEM ID" "COLOR" "PRICE"