in this code we have tree func to build this app:
-
get ---> to get current count
- everyone see this func and can call it and have view of it
-
increase ---> to increment current count by _elevator argument --->
- everyone can see this function and just can call it
-
decrease---> to decrement current count by reducer argument
- everyone can see this function and just can call it
if our current count is 0 we can decrease it because the result will be negative