SHELL

increment number bash

i=$((i+1))
((i=i+1))
let "i=i+1"

increment variable bash

#Increment varible in bash script
((i++))
((i=i+1))
i=$((i+1))
let "i++"
let "i=i+1"

Increment in Bash

i=12

echo $i

i=$((i+1))

echo $i