i++; will just increament value of i by 1.
in c,or c++
i++,++i are same if. if they are not used with other variable.
in the same way --i,i-- are same.
now the value of i is simply 6;
again value of i is 6;
but u just consider statement
the value of c is 5, i is 6.
the value of c is 6,i is 6;