Tutorial #3

1. Tutorial #3 Summer 2005 Liza Fireman

2. Keywords Liza Fireman

3. Names – legal or not? the_one temp do_it! intro2cs drink-me 1st_street counter • ! is not legal • - is not legal • 1 can not be first Liza Fireman

4. Names – legal or not? int the_num, the_Num; double Double; double main; int printf; Liza Fireman

5. total_cost = work_hours * price_per_hour + parts_cost; payment = total_cost * (1 + vat); Significat names cst = wh * pphr + prt; pt = cst * (1 + v); Liza Fireman

6. 27 26 25 24 23 22 21 20 Types 2 bytes = 16 bits  32,000 4 bytes = 32 bits  2,000,000,000 short int long ≥ ≥ = 20 + 22 + 23 = 1 + 4 + 8 = 13 Liza Fireman

7. Hello World Program 2 bytes = 16 bits  65,000 4 bytes = 32 bits  4,000,000,000 unsigned short unsigned int unsigned long Liza Fireman

8. Types float double long double ≥ ≥ חזקה 10 מנטיסה ±= Liza Fireman

9. Types 5000 , -30 256L , 30l 256U , 30u 12300ul 1234567UL 1.5 , -3.0, 4.2e5 , 10e-60 36.7F , 4.2e+5f 36.7L , .5l Liza Fireman

10. Characters - ASCII Liza Fireman

11. chars #include <stdio.h> int main() { char ch = ‘a’; char ch2 = 67; } Liza Fireman

12. chars #include <stdio.h> int main() { char ch = 65; printf(“%d\n”, ch); printf(“%c”, ch); } • 65 • A Liza Fireman

13. chars #include <stdio.h> int main() { printf(“%c %d\n”, 97, 97); } • a 97 Liza Fireman

14. chars #include <stdio.h> int main() { printf(“%c %d\n”, ‘b’, ‘b’); } • b 98 Liza Fireman

15. chars #include <stdio.h> int main() { printf(“%c %c %c\n”, ‘b’, ‘b’+1, ‘b’ + 2); } • b c d Liza Fireman

16. chars #include <stdio.h> int main() { char letter; printf("Enter a lowercase letter: "); scanf("%c", &letter); printf("In uppercase: %c", (letter - 'a') + 'A'); } • Enter lowercase letter: f In uppercase: F Liza Fireman

17. getchar #include <stdio.h> int main() { char letter; printf("Enter a lowercase letter: "); letter = getchar(); printf("In uppercase: %c", (letter - 'a') + 'A'); } Liza Fireman

18. Types char → short → int → long → float → double → long double 7 / 3 7.0 / 3 7 / 3.0 • = 0 Liza Fireman

19. Types int apples = 30, children = 12; double juice_from_apple = 0.1; double tot_orange_juice = 5.4; double liters_per_cup = 0.3; double orange_juice_per_child = tot_orange_juice / children; double apple_juice_per_child = (apples / children) * juice_from_apple; double total_juice_per_child = orange_juice_per_child + apple_juice_per_child; • int / int • double / int • int * double • double + double Liza Fireman

20. Types int apples = 30, children = 12; double juice_from_apple = 0.1; double tot_orange_juice = 5.4; double liters_per_cup = 0.3; … int minimum_cups_per_child = total_juice_per_child / liters_per_cup; • int = double • double / double Liza Fireman

21. casting #include <stdio.h> int main() { double d; d = (double)3 / 2; } Liza Fireman

22. casting #include <stdio.h> int main() { int x = 2; printf(“%lf”, (double)x); } Liza Fireman

23. casting #include <stdio.h> int main() { int cake_num = 5, children = 3; double cake_per_child = } cake_num / children Liza Fireman

24. casting #include <stdio.h> int main() { int cake_num = 5, children = 3; double cake_per_child = } (double)cake_num / children Liza Fireman

25. casting #include <stdio.h> int main() { int cake_num = 5, children = 3; double cake_per_child = } cake_num / (double)children Liza Fireman

26. casting #include <stdio.h> int main() { int cake_num = 5, children = 3; double cake_per_child = } (double)(cake_num / children) Liza Fireman

27. operators Liza Fireman

28. Operators Liza Fireman

29. Operators • c=b • t = 34 s = 50 int main() { char c; int t = 5, s = 7 ; double x = 8.5, y = 7.2 ; c = 'a' ; t = c + 1; c = t; printf("c = %c\n", c); t = (t - 'a' + 3) * x; s = s * y; printf("t = %d , s = %d\n", t , s); … } • ‘a’ + 1 = ‘b’ = 98 • ‘b’ - ‘a’ + 3 = 1 + 3 = 4 • 7 * 7.2 = 50.4 • 4 * 8.5 = 34 Liza Fireman

30. Operators int main() { char c; int t = 5, s = 7 ; double x = 8.5, y = 7.2 ; … x = (int)(y * s); y = (int)y * s; printf(“x = %lf , y = %lf\n", x , y); return 0 ; } • 7.2 * 50 = 360 • 7 * 50 = 350 • x=360.000000, y=350.000000 Liza Fireman

31. Operators int x , y; x = 8 ; y = ++x; printf(“x = %d y = %d”,x ,y); • x= x + 1; • y = x; • x=9, y=9 Liza Fireman

32. Operators int x , y; x = 8 ; y = x++; printf(“x = %d y = %d”, x ,y); • y = x ; • x= x + 1 ; • x=9, y=8 Liza Fireman

33. Operators int n = 5, x , y; x = n++; y = ++n; printf(x = %d , y = %d , x , y ) ; • x=5, y=7 Liza Fireman

34. Operators int x = 5, y ; y = -x + x ; y = ++x ; y = x++ ; x = ++x + x++ ; • -5 + 5 = 0 • x = 6, y= 6 • x = 7, y = 6 Liza Fireman

35. Int and double 10 + 20 – 5 – 2 10 * 20 / 8 / 5 10 + 20 * 5 x = 4; y = 5; z = y += x *= 5; = 23 = 5 = 110 Liza Fireman

36. getchar #include <stdio.h> int main() { char ch; ch = getchar(); if ((ch >= ‘a’ && ch <= ‘z’) || (ch >= ‘A’ && ch <= ‘Z’) printf(“a letter”); else printf(“not a letter”); } Liza Fireman