# Sample Midterm

These are sample questions that are very similar to the ones I will ask on the midterm.

1. Which of the following is not a valid C variable name?
1. hello
2. chomp_burp
3. whilex
4. more-more-more
5. TrUcKiNg

2. Evaluate the following expressions, assuming a = 1, b = -3, and c = 0. Treat them independently, so (for example) after evaluating (b), the above values are used for (c).
1. a + b < c
2. c == !a == c
3. a = ++b; give the values of both a and b as well
4. a– == !b; give the value of a as well
5. a / b

3. True or False: If x = -1, then if (x) printf("1"); else printf("2"); prints 2.

4. What are all possible outputs of the following code fragment?
void f(int a, int b)
{
printf("%d %d\n", a, b);
}

void main(void)
{
int i = 5;
f(++i, ++i);
}

5. Given the definitions
int numbs[10];
int *ptr = numbs;
which of the following are equivalent, and why?
1. numbs[3]
2. numbs + 3
3. *(numbs + 3)
4. *(ptr + 3)
5. *ptr + 3

6. Use the following code fragment to answer parts (a), (b), and (c):
for(x = i = 0; i <= 100; i += 2, x += i);
1. In one short sentence, what does this for loop do?<br>
2. Is the following while loop equivalent? If not, how does its result differ? (: look at the values of both x and i.)
x = i = 0;
while( i++ <= 100)
x += ++i;
3. Does the following for loop do the same thing? If not, what does it do?
for(x = i = 0; i <= 100; i++){
if (!(i % 2))
continue;
x = x + i;
}

7. What does this function do?
char *x(char *s, char c)
{
char *r = NULL;

do{
while(*s && *s != c)
s++;
if (*s)
r = s;
} while(*s++);
return(r);
}

8. The following segment of code is supposed to print the number of times the routine a_again is called. Yet, regardless of the input, it prints 0. Why? How would you fix it?
void a_again(int acount)
{
++acount;
}

int main(void)
{
int c;
int counter = 0;

while((c = getchar()) != EOF)
if (c == ’a’ || c == ’A’)
a_again(counter);

printf("%d\n", counter);
return(0);
}

 You can also obtain a PDF version of this. Version of October 21, 2015 at 5:20PM