How do I auto-increment and auto-decrement in a bash shell script?

shoebill

The post and pre increment and decrement arithmetic operators. ++ & -- The pre and post determine if the value is returned before or after.

This applies to auto-decrement as well.
i++ gets the current value of i before and then increments it.
++i increments variable i and then uses the result after.

StartNumber=0

while (($StartNumber < 10))
do
  StartingNumber=$(($StartNumber < 10))
  let "++StartNumber"
  echo $StartNumber
done

Running this give the following output:

$ ./arithmetic.sh
1
2
3
4
5
6
7
8
9
10

The let command is not the only way to increment or decrement.