1. Tutorial #4
Summer 2005

2. If int main() { if (30) printf("this will ___ be printed"); }
return 0;

3. If
int main() {
if (0)
printf("this will ___ be printed"); }
return 0;

4. If int main() { if (-24) printf("this will ___ be printed"); }
return 0;

5. If int main() { int digit; …
if ((digit == 0) || ((digit > 3) && (digit != 7))) …. }

6. if … else if … else #include <stdio.h> int main() { char c;
if ((c = getchar() != ‘\n’) {
if ((c >= ‘a’ && c <= ‘z’) || (c >= ‘A’ && c<= ‘Z’)
printf(“A letter\n”); }
else
printf(“not a letter”);
printf(“End of line”);

7. if … else if … else #include <stdio.h> int main() { char c;
if ((c = getchar() != ‘\n’)
if ((c >= ‘a’ && c <= ‘z’) || (c >= ‘A’ && c<= ‘Z’)
printf(“A letter\n”);
else
printf(“not a letter”);
printf(“End of line”); }

8. if … else if … else #include <stdio.h> int main() { char c;
if ((c = getchar() != ‘\n’)
if ((c >= ‘a’ && c <= ‘z’) || (c >= ‘A’ && c<= ‘Z’)
printf(“A letter\n”);
else
printf(“not a letter”); }

9. if … else if … else #include <stdio.h> int main() { char c;
if ((c = getchar() != ‘\n’)
if ((c >= ‘a’ && c <= ‘z’) || (c >= ‘A’ && c<= ‘Z’)
printf(“A letter\n”);
else
printf(“End of line”); }

10. if … else if … else #include <stdio.h> int main() { char c;
if ((c = getchar() != ‘\n’)
if ((c >= ‘a’ && c <= ‘z’) || (c >= ‘A’ && c<= ‘Z’)
printf(“A letter\n”);
else;
else
printf(“End of line”); }

11. if … else if … else #include <stdio.h> int main() {
int a = 2, b = 1;
if (a > 2 || b < 3)
printf(“1”);
else
printf(“2”);
if (a > 2)
printf(“1”);
else if (b < 3)
else
printf(“2”); }

12. if … else if … else #include <stdio.h> int main() {
int a = 2, b = 1;
if (2 < a < 3)
printf(“2 < a < 3”); }

13. if … else if … else #include <stdio.h> int main() { int color;
scanf(“%d”, &color);
if (color == 1)
printf(“red\n”);
else if (color == 2)
printf(“yellow\n”);
else if (color == 3)
printf(“blue\n”);
return 0; }

14. Switch #include <stdio.h> int main() case 2: {
int color;
scanf(“%d”, &color);
switch (color)
case 1:
printf(“red\n”);
break;
case 2:
printf(“yellow\n”);
break;
case 3:
printf(“blue\n”); }
return 0;

15. Switch #include <stdio.h> case 2: int main() printf(“yellow\n”);{
int color;
scanf(“%d”, &color);
switch (color)
case 1:
printf(“red\n”);
break;
case 2:
printf(“yellow\n”);
break;
case 3:
printf(“blue\n”);
default:
printf(“No color\n”); }
return 0;

16. Switch #include <stdio.h> int main() { int color;
scanf(“%d”, &color);
switch (color)
case 1:
printf(“red\n”);
case 2:
printf(“yellow\n”);
case 3:
printf(“blue\n”); }
return 0;

17. Operators… #include <stdio.h> #include <stdio.h>
int main() {
int a, b;
scanf(“%d%d”, &a, &b);
if (a == 0 || b/a > 1)
...
return 0; }
#include <stdio.h>
int main() {
int a, b;
scanf(“%d%d”, &a, &b);
if (b/a > 1 || a == 0)
...
return 0; }

18. Operators… #include <stdio.h> int main() { int a; … if (a++)
printf("a was not zero");
else
printf("a is not zero");
return 0; }

19. Operators… #include <stdio.h> int main() { int x, y;
scanf(“%d %d”, &x, &y);
if ((x = y) != 0)
...
return 0; }

20. Operators… #include <stdio.h> int main() { int x = 2, y, z;
return 0; }

21. Operators… int x = 2, y = 1, z = 0; x = x && y || z;
#include <stdio.h>
int main() {
int x = 2, y = 1, z = 0;
x = x && y || z;
printf(“%d\n”, x);
printf(“%d\n”, x || !y && z);
x = y = 1;
z = x++ -1
printf(“%d\n”, z);
z += -x y;
printf(“%d\n”, x);
z = x / ++x;
return 0; }

22. scanf double age, height; int res;
printf("enter your age and height");
res = scanf("%lf %lf", &age, &height);
if (res != 2) {
printf(“scanf failed”);
return -1; }

23. ?: char ch; int x; … if (ch >= ‘a’ && ch <= ‘z’) x = 8; else

24. ?:
char ch;
int x; …
x = ((ch >= ‘a’ && ch <= ‘z’) ? 8 : 7);

25. ?:
char ch;
int x; …
(ch >= ‘a’ && ch <= ‘z’) ? x = 8 : x = 7;

26. while x = -2; while (x < 0) { printf("x is still negative :(\n");
x = x + 1; }
printf("x is no longer negative.\n");

27. while #include <stdio.h> int main() { char ch = ‘a’;
while (ch <= ‘z’)
printf(“%d: %c\n”, ch, ch);
ch++; }

28. While loops double age; printf("enter your age: ");
scanf("%lf", &age);
while (age < 18) {
printf("Invalid age, please try again: "); }
printf("Welcome to C-Stuff.com, the");
printf("#1 adult site on the web!\n");

29. While Loop #include <stdio.h> int main() { int n = 3; while (n)
printf(“%d\n”, n--);
return 0; }

30. While Loop #include <stdio.h> int main() { int n = -3; while (n)
printf(“%d\n”, n++);
return 0; }

31. While Loop #include <stdio.h> int main() { char ch;
ch = getchar();
while (ch == ‘ ‘ || ch == ‘\n’)
return 0; }

32. For Loop #include <stdio.h> int main() { int secs; }
for (secs = 2; secs > 0; secs--)
printf(“%d seconds!\n”, secs); printf(“The End!”);
return 0 ; }

33. for #include <stdio.h> int main() { char ch;
for (ch = ‘a’; ch <= ‘z’; ++ch)
printf(“%d: %c\n”, ch, ch); }

34. For Loop #include <stdio.h> int main() { int i; }
for (i = 0; i < 60; i += 10)
printf(“%d \n”, i);
return 0; }

35. For Loop #include <stdio.h> int main() { int i; }
for (i = 0; i < 60; i += 10)
printf(“%d \n”, i);
return 0; } ;

36. For Loop #include <stdio.h> #include <stdio.h> int main(){
int count = 1;
for ( ; count <= 5; ++count)
printf(“%d \n”, count);
return 0; }
#include <stdio.h>
int main() {
int count = 1;
while (count <= 5)
printf(“%d \n”, count);
++count; }
return 0;