<C Primer Plus>7 The Comma Operator

 1 #include <stdio.h>
 2 #include <math.h>
 3 int main(void){
 4     const int FIRST_OZ = 46;
 5     const int NEXT_OZ = 20;
 6     int ounces, cost;
 7 
 8     printf("  ounces  cost\n");
 9     for (ounces = 1, cost = FIRST_OZ; ounces < 16;ounces++,cost += NEXT_OZ){/// initialize and proess the value..
10         printf("%5d    $%4.2f\n", ounces, cost / 100.0);
11     }
12     
13     return 0;
14 }

x = (y = 3, (z = ++y + 2) + 5);
the result is x = 11;
REMEBER:
The comma being a sequence point guarantees that the side effects of the left subexpression occur before the right subexpression is evaluated.