thanosxx:
on starter kit book ,before SETUP function there is 3 int
You mean these extra two lines from the sketch you attached to your post:
int buttons[6];
int buttons[0]=2;
This is an example of why it's important to take the time to study the code instead of just blindly typing it out. Then you might understand why it would make sense to either add or remove those two lines instead of seeing them as inscrutable parts of a magical incantation.