Increment variable value by 1 ( shell programming)

Question

I am a beginner to shell programming and it sounds like a very stupid question but i cant seem to be able to increase the variable value by 1. I have looked at tutorial but

Answer 1

The way to use expr:

i=0
i=`expr $i + 1`

the way to use i++

((i++)); echo $i;

Tested in gnu bash