When a method is called, who is responsible for ensuring that
the precondition is valid?
- A.
The person who is using the program.
- B.
The programmer who called the method.
- C.
The programmer who wrote the method.
- D.
The programmer who implemented the Java Runtime System.
What will happen if a method is executed and the precondition
for the method is not met?
- A.
An exception will be thrown.
- B.
The program will loop indefinitely.
- C.
The system will crash.
- D.
Any of the above results could happen.
Answer true or false for this statement:
When programming in teams, the specification of a method must
be written by the person writing the code for the method.
Answer true or false for this statement:
When programming individually (not in a team), there is no need to
write a specification for a method.
If the precondition fails, it is a good idea to throw an exception
that will generally halt the program.
Why is the program halted?
- A.
The Java Runtime System forbid continuation.
- B.
The method is no longer guaranteed to make the postcondition true.
- C.
The method's memory requires have become exponential (or worse).
- D.
The method's running time has become exponential (or worse).
What information do you need to see in order to make effective
use of the printNumber method in Section 1.1?
- A. Just the method's implementation.
- B. Just the method's specification.
- C. Both the implementation and specification.
Which of these function calls will cause an exception to be thrown
when x is 42.
(x is an int variable).
- A.
if (0 < x)
throw new IllegalArgumentExcpetion("Bad x");
- B.
if (0 == x)
throw new IllegalArgumentExcpetion("Bad x");
- C.
if (0 > x)
throw new IllegalArgumentExcpetion("Bad x");
- D.
None of the above will cause an exception when x is 42.
Multiple Choice
Section 1.2
Running Time Analysis
|
What does a run-time analysis usually count?
- A.
The number of arithmetic and other operations required for the program
to run
- B.
The number of megabytes required for the program to run
- C.
The number of seconds required for the program to run
- D.
The number of seconds plus the number of megabytes
- E.
The number of seconds times the number of megabytes
Which of these is the correct big-O expression for
1+2+3+...+n?
- A. O(log n)
- B. O(n)
- C. O(n log n)
- D. O(n²)
Which of the following formulas in big-O notation best represent the
expression n²+35n+6?
- A. O(n³)
- B. O(n²)
- C. O(n)
- D. O(42)
Answer true or false for this statement:
For all possible inputs, a linear algorithm to solve a
problem must perform faster than a quadratic algorithm to solve the
same problem.
Answer true or false for this statement:
True or false: An algorithm with worst case time behavior of 3n takes at
least 30 operations for every input of size n=10.
What term is used to describe an O(n) algorithm.
- A.
Constant
- B.
Linear
- C.
Logarithmic
- D.
Quadratic
Here is some code for an integer variable n:
while (n > 0)
{
n = n/10; // Use integer division
}
What is the worst-case time analysis for the above loop?
- A. O(1)
- B. O(log n)
- C. O(n)
- D. O(n²)
Express the formula (n - 2)*(n - 4) using big-O notation:
- A. O(1)
- B. O(8)
- C. O(log n)
- D. O(n)
- E. None of the above
Multiple Choice
Section 1.3
Testing and Debugging
|
Why is it important to test boundary values when testing programs?
- A.
Calculating by hand, it's easy to find the
right answers for boundary values.
- B.
Debuggers are easier to use when testing boundary values.
- C.
In practice, a large proportion of errors arise from boundary values.
- D.
The correct execution of a function on all boundary values
proves a function is correct.
How may boundary values for a method be found?
- A.
Pick values that are one step away from different behavior.
- B.
Pick values that make the precondition equal to the postcondition.
- C.
Pick values where the precondition is false.
- D.
Pick values where the postcondition is false.
Which software tool will best help you determine whether your
test cases are fully exercising your code?
- A. Compiler
- B. Debugger
- C. Make
- D. Pine
- E. Profiler
