How to do array operation in busybox

[Bastian Bittorf]

* Pratik Prajapati <pratik.prajapati12 at gmail.com> [26.06.2015 08:44]:
> 305: shift
> 306: index=0307: for arg;                               308: do
> 309:   x[$index]=$arg310:   ((index++))         311: done
> 
> but i got error:  syntax error: unexpected "(" (expecting "}")

google for 'POSIX shell array' or use 'bash'

bye, bastian