#Bash shell supports 1-D array variables
NAMES=(max helen sam zach)
echo ${NAMES[0]}
echo ${NAMES[1]}
echo ${NAMES[2]}
echo ${NAMES[3]}

VALUE=10
NEW=5
let "VALUE=VALUE * 10 + NEW"
echo $VALUE

VALUE=10
((VALUE=VALUE * 10 + NEW))  #synonym for let
echo $VALUE

COUNT=1; VALUE=10
let "COUNT=COUNT+1" VALUE=VALUE*10+NEW
echo $COUNT
echo $VALUE

#conditional expressions
#2 syntax, (()) and [[]]

age=35
if ((30 < age && age < 60)); then
	echo "Wow, in $((60-age)) years, you will be 60!"
else
	echo "You are too young or too old to play."
fi

age=25
if [[ 30 < $age && $age < 60 ]]; then  #take note of white spaces
	echo "Wow, in $((60-age)) years, you will be 60!"
else
	echo "You are too young or too old to play."
fi