using a cirular index

[jimberger]

Hello,
i am trying to implement an circle using an index. I have an index of 0 to 7. i want to increase the index 3 places at a time but when it gets to 7 and want it to wrap round to 0 and so on. for example if the index is on 6 then after increment then the index will be on 1. any ideas on how i can do this?
thanks for your help

 

[xwb]

You need to increment first then modulus 8. i.e.

x = (x + 3) % 8;

 

[hughLg]

if ((num += 3) >= 7)
   num = 0;