page 9 #include int main(){ int i = 1; float weight,sum=0; while (i <= 10) { printf("Enter weight : "); scanf("%f",&weight); sum+=weight; i++; } printf("Sum of weights = %.2f",sum); return 0; } ............................................. page 10 #include int main() { int i = 1; float weight,sum=0; do { printf("Enter weight : "); scanf("%f",&weight); sum+=weight; i++; } while (i <= 10); printf("sum of weights = %.2f",sum); return 0; } ........................................... page 11 #include int main() { int i ; float weight,sum=0; for (i=1; i<=10; i++) { printf("Enter weight : "); scanf("%f",&weight); sum+=weight; } printf("sum of weights = %.2f",sum); return 0; } ............................... page 13 #include int main() { int Price,Amount,Pay; printf("Enter Amount : "); scanf("%d",&Amount); while (Amount != 0) { printf("Enter Price : "); scanf("%d",&Price); Pay=Price*Amount; printf("You must pay %d baht\n",Pay); printf("* * * * * * * * * * * * * * *\n"); printf("Enter Amount : "); scanf("%d",&Amount); } printf("* * * * * * * * * * * * * * *\n"); printf("Thank you"); return 0; } ............................... page 14 แบบ while printf("Enter number (between 10 and 20): "); scanf("%d", &num); while (num < 10 || num > 20) { printf("Error data !!!!\n"); printf("Enter number (between 10 and 20) : "); scanf("%d", &num); } แบบ do while do { printf("Enter number (between 10 and 20): "); scanf("%d", &num); } while (num < 10 || num > 20); ............................... page 15 แบบ while printf("Enter number : "); scanf("%d", &number); while (number != 0) { ทำงาน; printf("Enter number : "); scanf("%d", &number); } แบบ do while do { printf("Enter number : "); scanf("%d", &number); if (number!=0) ทำงาน; } while (number != 0); ..................................... page 18 #include int main( ) { int num, sum, count; char ch; do { sum=0; count=0; do { printf("Enter number : "); scanf("%d", &num); fflush(stdin); sum += num; count++; } while (sum <= 200); printf("Enter number %d times", count); printf("\n\nExit program (Y/N) ? "); scanf("%c", &ch); } while ((ch!='y')&&(ch!='Y')); return 0; }