busybox/shell/ash_test/ash-arith/arith1.sub

# test of redone post-increment and post-decrement code
(  echo $(( 4-- ))   )
(  echo $(( 4++ ))   )
(  echo $(( 4 -- ))  )
(  echo $(( 4 ++ ))  )

#ash# (( array[0]++ ))
#ash# echo ${array}

#ash# (( array[0] ++ ))
#ash# echo ${array}

#ash# (( a++ ))
#ash# echo $a
#ash# (( a ++ ))
#ash# echo $a
      a=2

echo 6 $(( a ++ + 4 ))
echo 3 $a

echo 7 $(( a+++4 ))
echo 4 $a

echo 0 $(( a---4 ))
echo 3 $a

echo 7 $(( a -- + 4 ))
echo 2 $a

echo -2 $(( a -- - 4 ))
echo 1 $a

#ash# (( ++ + 7 ))

#ash# (( ++ ))
(  echo $(( +++7 ))  )
# ++ is not a inc operator on non-variable, it is the + + sequence
echo $(( ++ + 7 ))
#ash# (( -- ))