Missing new lines in Bash in passing function to variable

Question

Why in this case doesnt generate new lines in Bash:

#!/bin/bash

function sample() {
    local DATA=""
    DATA="test1"$'\n'
    DATA="${DATA}test2"$'\n'
    echo ${DATA}
}


DATA=$(sample)
printf "%s" "${DATA}"

Answer 1

$DATA is expanded, and all whitespace (including newlines) are used for word-splitting, before echo ever runs. You should always quote parameters expansions.

sample() {
    local DATA=""
    DATA="test1"$'\n'
    DATA="${DATA}test2"$'\n'
    echo "${DATA}"
}

Answer 2

You must use the -e option of echo for it to interpret the \n character:

echo -e "${DATA}"