echo $STRING

first second third fourth fifth

array[0] = first
array[1] = second

IFS=' ' read -a list <<< $STRING

echo ${list[@]}

list=( $STRING )

declare -a list=( $STRING )

$list=( first second third )
$IFS=":" echo "${list[*]}"
first second third
$IFS=":" ; echo "${list[*]}"
first:second:third