CMSC 104, Fall 2001
Exam 3 Sample Questions
True/False Questions
Circle TRUE or FALSE for each of the following questions.
- TRUE/FALSE
switch is a legal identifier in C.
- TRUE/FALSE
The statement printf("%5d\n", 3); prints the number 3 five
times.
- TRUE/FALSE
The statement printf("%d\n", 3, 5); prints the number 3 five
times.
- TRUE/FALSE
The statement printf("%5d\n", 3); prints the number 5 three
times.
- TRUE/FALSE
A function prototype tells the compiler the type of the value that is
returned by the function.
- TRUE/FALSE
A function prototype tells the compiler nothing about the value that is
returned by the function.
- TRUE/FALSE
When a function is called, its local variables initially contain the
value 0.
- TRUE/FALSE
If a is a variable of type int, after the statement
a = 17.76 has been executed, a has a value of 17.
- TRUE/FALSE
If a is a variable of type int, after the statement
a = 17.76 has been executed, a has a value of 18.
- TRUE/FALSE
If a is a variable of type float, after the statement
a = 17 has been executed, a has a value of 17 .
- TRUE/FALSE
If a is a variable of type float, after the statement
a = 17 has been executed, a has a value of 17.0.
- TRUE/FALSE
A function with return type void always returns the value 0.
- TRUE/FALSE
When a function is called, the number of arguments passed should match
the number of formal parameters given in the function's prototype.
- TRUE/FALSE
After a function has returned, the values stored in its local variables
are copied into variables in the calling function that have the
same name.
- TRUE/FALSE
The values stored in the local variables of a function are not saved
when the function exits.
- TRUE/FALSE
The prototype of a function is used mainly as a comment to the
reader, but is not useful to the compiler.
- TRUE/FALSE
If the integer variables a and b are holding the values 0 and 1,
respectively, what is the value of the following expression :
( a || b ) ?
- TRUE/FALSE
If the integer variables a and b are holding the values 0 and 1,
respectively, what is the value of the following expression :
( a && b ) ?
- TRUE/FALSE
If the integer variables a and b are holding the values 1 and 2,
respectively, what is the value of the following expression :
( a + b ) ?
- TRUE/FALSE
If the integer variables a and b are holding the values 0 and 6,
respectively, after the statement a += b++ the new values of
a and b are both 7.
- TRUE/FALSE
If the integer variables a and b are holding the values 0 and 6,
respectively, after the statement a += ++b the new values of
a and b are both 7.
- TRUE/FALSE
If the integer variables a and b are holding the values 0 and 6,
respectively, after the statement a += b++ the new values of
a and b are 6 and 7, respectively
- TRUE/FALSE
When an array is passed to a function, only the address
of the array is passed to the function.
- TRUE/FALSE
When an array is passed to a function, a copy of the elements
is made and passed to the function to manipulate.
- TRUE/FALSE
When an array is passed to a function, the address
of the array is passed to the function and a copy of the
elements is made for the function to manipulate.
- TRUE/FALSE
The preprocessor directive #define RING 1 tells the C
preprocessor to replace each occurrence of the constant RING
with 1.
- TRUE/FALSE
The default case is required in the
switch selection structure.
- TRUE/FALSE
The default case must be the last case in the
switch selection structure.
- TRUE/FALSE
The break statement is required in the
default case of the switch
selection structure.
- TRUE/ FALSE
An array can store many types of values simultaneously.
- TRUE/ FALSE
Array subscripts must always start at 0.
- TRUE/ FALSE
The fourth element of an array named bob is bob[4]
- TRUE/ FALSE
All arrays with 10 elements require the same amount of memory.
Multiple Choice Questions
- What is the output of the following code fragment?
<![CDATA[
int a = 3, b = 17 ;
a = b % a ;
b = ++a + 5 ;
printf("a = %d, b = %d\n", a, b) ;
]]>
[a.] a = 3, b = 8
[b.] a = 2, b = 7
[c.] a = 3, b = 7
[d.] a = 2, b = 8
[e.] None of the above.
- For the following code fragment, TRUE has been #defined to be 1,
and FALSE has been #defined to be 0.
Note that there is an assignment operator in the condition of the first
if statement.
The output of the following program fragment is:
<![CDATA[
test = FALSE ;
if (test = TRUE) {
printf("Beam down the landing party.\n") ;
} else if (test == FALSE) {
printf("Jim, he's dead.\n") ;
} else if (test == TRUE) {
printf("Scotty, four to beam up.\n") ;
}
]]>
[a.] Beam down the landing party.
[b.] Jim, he's dead.
[c.] Scotty, four to beam up.
[d.] No output is produced
- Which of the following is the function prototype for a
function AlphaBeta that takes two double parameters
and does not return any values.
[a.] AlphaBeta(double, double);
[b.] void AlphaBeta(double, double);
[c.] void AlphaBeta(double x, y);
[d.] double AlphaBeta(double, double);
- Which of the following is the function prototype for a
function Bob that takes one double parameter
and returns an integer value.
[a.] void Bob (int, double)
[b.] void Bob (double, int);
[c.] int Bob (double)
[d.] int Bob (int, double)(
- Which of the following is the function prototype for a
function Bill that takes two integer parameters
and returns a double value
[a.] Bill (int, int);
[b.] double Bill (int, int);
[c.] void Bill (double, int, int);
[d.] double Bill (int * 2)
- When an array parameter is passed to a function
[a.] the elements of the actual array parameter are copied into the
elements of the formal array parameter.
[b.] the elements of the formal array parameter are copied into the
elements of the actual array parameter.
[c.] the formal parameter is a pointer that holds the address of the
actual array parameter.
[d.] the programmer must write code which allocates enough space for
the function to store the array.
- Which of the following statements will print out the float variable x
with exactly 1 decimal place, e.g. 123.4
[a.] printf ("%.1f\n", x);
[b.] printf ("%1f\n", x);
[c.] printf ("%.1e\n", x);
[d.] printf ("%1e\n", x);
- A single C statement that assigns the sum of x and
y to z and then increments the
value of x by 1 after the calculation.
[a.] z = y + (x + 1);
[b.] z = ++x + y;
[c.] z = y + x++;
[d.] none of the above
- A single C statement that decrements the variable x by
one then subtracts it from the variable total is
[a.] total = total - x--;
[b.] total -= --x;
[c.] total -= (x - 1);
[d.] none of the above
- A single C statement that adds the variable x to the
variable total and then decrements x
by one is
[a.] total = total + x--;
[b.] total += --x;
[c.] total += (x - 1);
[d.] none of the above
- Assuming that the variables x and product
each have the value 5, then the new values of x
and product after the statement product *= x++;
are
[a.] product = 25 and x = 5
[b.] product = 25 and x = 6
[c.] product = 30 and x = 5
[d.] product = 30 and x = 6
- Assuming that the variables high and low
contain the values 3 and 5, respectively, then the new values of
high and low after the statement
high *= --low + 4 are
[a.] high = 24 and low = 4
[b.] high = 24 and low = 8
[c.] high = 19 and low = 4
[d.] high = 19 and low = 8
- Assuming that the variables a and b
contain the values 20 and 3, respectively, then the new values of
a and b after the statement
a -= --b * 2 are
[a.] a = 14 and b = 2
[b.] a = 16 and b = 2
[c.] a = 14 and b = 4
[d.] a = 16 and b = 4
Short Answers
In the following questions, no syntax errors have been put in deliberately.
(So, "there is a syntax error" is NOT the right answer and will
receive no credit.) Please mark your final answer clearly. In order
to receive partial credit, you must show your work.
- Write a function called SumArray that returns the sum of
the first n elements of an array of floats, where the array and n
are passed to it.
- Give a function prototype for a function called Hypotenuse
that takes two double precision floating point arguments, side1
and side2 and returns a double precision
floating point result.
- Give a function prototype for a function called Smallest
that takes three integer arguments, x, y
and z and returns an integer.
- Give a function prototype for a function called Instructions
that does not have any arguments and does not return a value.
- What happens if your program tries to access an array element with an out-of-range subscript?
- How are the elements of an array stored in memory ?
- What is the output of the following program? Don't wory about
the exact number of spaces to appear before or after any numeric
output. If the program goes into an infinite loop, you need show only
the first five lines of output. Assume that the program as shown
compiles correctly.
<![CDATA[
#include <stdio.h>
int Deep(int, int) ;
int Space(int) ;
main()
{
int a = 2, b = 3, c = 3 ;
a = Deep (b + 5, c) ;
b = Space (c) ;
printf ("main: a = %d, b = %d, c= %d\n", a, b , c) ;
}
int Deep (int x, int y)
{
int z ;
z = x - y ;
printf ("Deep: x = %d, y = %d, z = %d\n", x, y, z) ;
return (z) ;
}
int Space (int c)
{
int a, b ;
a = 1 ;
b = c * 2 + a ;
a = b + 5 ;
c = Deep (a, b) ;
printf ("space: a = %d, b = %d, c = %d\n", a, b, c) ;
return (b) ;
}
]]>
- Which of C's data types can be used in an array.
- In a one-dimensional array declared with n elements, what is the
index of the last element ?
- Write the statements that would declare a 10-element integer array and
initialize all of its elements to 1.
- Write a function called Average that takes three integer
parameters n1, n2, and n3 and returns the value of the
average of the three as a double.
- Write a procedure called PrintBox that will print a
rectangle made up of any character passed to it. Here is the prototype:
<![CDATA[
void PrintBox (int rows, int columns, char ch);
]]>
This call to PrintBox, PrintBox(3, 10, '$');
should print:
<![CDATA[
$$$$$$$$$$
$$$$$$$$$$
$$$$$$$$$$
]]>
- Write a function called NumDigits that has a single formal parameter
of type int and returns the number of digits in that integer.
- Fill in the blanks below. The function FindNet computes
a worker's weekly net pay given hours (an integer),
rate (a double), and exempt
(a boolean) as input parameters. The net pay for the worker should be returned
as a double. If the worker turns in more than forty hours and the value of
exempt is FALSE, then pay 1 1/2 times the normal rate ("time and a half") for
any hours worked over forty. If gross pay exceeds $800, subtract 33% for
taxes. Otherwise, subtract 25% for taxes. Include a statement to print the
worker's hours and net pay for the week. (The net pay will be in dollars and
cents, so choose the output format accordingly. The number of underscore
characters shown is not necessarily an indication of the length of the correct
response.)
<![CDATA[
________ FindNet ( int hours, ________ ______ , int _______ )
{
double ________ , __________ ;
int ___________ ;
if ( _______ > 40 _____ (!exempt ) )
{
extraHours = hours - 40;
grossPay = (40 * _______ ) + extraHours * (rate * _____);
}
else
{
grossPay = hours * _______ ;
}
if (grossPay > ________ )
{
netPay = grossPay - grossPay * _______ ;
}
______
{
netPay = grossPay - grossPay * _______ ;
}
________ ("Hours = %d and Net Pay = _______ \n", hours, netPay);
________ ( __________ );
}
]]>
- Write a set of one or more if statements that will
print out one of the brief messages given in the table below,
depending on a person's grade point average. Assume that the grade
point average has already been read into a variable called gpa.
Include code to print a warning message if the value of gpa is not in
the range 0.0 to 4.0.
| gpa range | student rating |
|---|
| 3.50 - 4.0 | Dean's list |
| 2.0 - 3.49 | Satisfactory |
| 1.0 - 1.99 | Probation |
| 0.0 - 0.99 | Suspended |
Determine the output generated by the following code segments,
assuming the surrounding program code (whatever it is) compiles correctly.
-
<![CDATA[
printf ("%.2f", 3.859143);
]]>
-
<![CDATA[
printf ("%.2f", 1.3e2);
]]>
-
<![CDATA[
int a = 2, b = 3;
b *= a;
a += b++;
printf ("%d %d\n", a, b);
]]>
-
<![CDATA[
void F (int x);
void G (int x);
main ()
{
G (3);
F (2);
G (5);
}
void F (int x)
{
printf ("%d ", x);
}
void G (int x)
{
F (x + 1);
printf ("%d ", x);
}
]]>
-
<![CDATA[
int X (int m);
int Y (int n);
main ()
{
int r, s;
r = X (5);
s = Y (10);
printf ("main: %d %d\n"), r, s);
}
int X (int m)
{
printf ("X: %d\n", m);
return (m + 2);
}
int Y (int n)
{
printf ("Y: %d %d\n", n, X (n));
return (n * 3);
}
]]>
-
<![CDATA[
int a = 5, b = 4;
b += a;
a -= ++b;
printf ("%d %d\n", a, b);
a = 13;
b = 4;
printf ("%d %d\n", a / b, b / a);
printf ("%d %d\n", a % b, b % a);
]]>
-
<![CDATA[
int n = 1234;
while (n > 0)
{
n /= 10;
printf ("%d\n", n);
}
]]>
-
<![CDATA[
int m;
for (m = 1; m <= 5; m++)
{
switch (m)
{
case 1:
printf ("one");
break;
case 2:
printf ("two");
break;
case 3:
printf ("three");
break;
default:
printf ("Default case");
}
printf ("\n");
}
]]>
-
<![CDATA[
int F1 (int a, int b);
int F2 (int b, int c);
main()
{
int a = 1, b = 2, c = 3;
c = F1 (a, b);
printf ("main: %d %d %d\n", a, b, c);
b = F2 (a, c);
printf ("main: %d %d %d\n", a, b, c);
}
int F1 (int a, int b)
{
printf ("F1: %d %d\n", a, b);
return a;
}
int F2 (int b, int c)
{
printf ("F2: %d %d\n", b, c);
return c;
}
]]>
-
<![CDATA[
int F1 (int a, int b);
int F2 (int a, int b);
main()
{
int a = 1, b = 2, c = 3;
c = F1 (a, b);
printf ("%d %d %d\n", a, b, c);
b = F2 (a, c);
printf ("%d %d %d\n", a, b, c);
a = F2 ( F1 (a, c), b);
printf ("%d %d %d\n", a, b, c);
b = F2 (a, c) / F1 (b, c);
printf ("%d %d %d\n", a, b, F1 (a, b) );
}
int F1 (int a, int b)
{
return (a + b + 3);
}
int F2 (int a, int b)
{
return ( (a + b) % 3 );
}
]]>