COMP 132 Practice Midterm Exam I Solution 75 points name: 1. (12 ...

The Pizza class does not implement the tastierThan method, even though it implements the Tasty
interface.
In main, an instance of Anchovy is passed as a parameter to the tastierThan method, but Anchovy
does not implement the Tasty interface.
In main, an instance of Salad is cast to Pizza - this would cause a ClassCastException at runtime.
2. (5 points) Was the Minesweeper lab a good example of the Model-View-Controller design pattern If
so, which parts of the code were the model and which parts were the view If not, why not
Yes. The model is the MineSweeperBoard class because it maintains the state of the application and
does all computation. The view is the MineSweeper class because it defines the GUI for the application.
3. Suppose that class ExampleClass in package comp132.exam1 declares a field as follows:
public static final int TWO = 2;
State whether or not each of the following method definitions would compile (your answer for each
should just be yes or no):
(a) (2 points) Assume this method is in class ExampleClass in package comp132.exam1.
public void printFour() { System.out.println(TWO + 2); } Yes
(b) (2 points) Assume this method is in class ExampleClass in package comp132.exam1.
public void addTwo() { TWO = TWO + 2; } No
(c) (2 points) Assume this method is in class SampleClass in package comp132.examples.
public void printTwo() { System.out.println(comp132.exam1.ExampleClass.TWO); }Yes
4. (8 points) What output is displayed by the following code snippet
int [] [] mat = new int [4][4];
for (int i = 0; i < mat.length; i++) {
for (int j = 0; j < mat[0].length; j++) {
mat[i][j] = (i + 1) * (j + 1);
}
}
int j = mat[0].length - 1;
for (int i = 0; i < mat.length; i++) {
System.out.println(mat[i][j]);
j = j - 1;
}
5. (5 points) Suppose that a program crashes because a method is called when its precondition is not
satisfied. Is this the fault of the programmer who wrote the method, or of the programmer who wrote
the code that called the method Why
The programmer who wrote the code that called the method. The precondition is a contract between the
method and calling code, and a method is only guaranteed to work correctly when its precondition is
satisfied. Hence, the second programmer broke the contract by calling the method when its precondition
was not satisfied.
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