EH17
1
CPSC150 CPSC150 EH17
Q1: Consider integer array values, which contains 5 elements. Which statements successfully swap the contents of the array at index 3 and index 4? a.
values[ 3 ] = values[ 4 ]; values[ 4 ] = values[ 3 ];
b.
values[ 4 ] = values[ 3 ]; values[ 3 ] = values[ 4 ];
c.
int temp = values[ 3 ]; values[ 3 ] = values[ 4 ]; values[ 4 ] = temp;
d.
int temp = values[ 3 ]; values[ 3 ] = values[ 4 ]; values[ 4 ] = values[ 3 ];
Q2: In this question, assume a class, Book, has been defined. Which set of statements creates an array of Book objects? a.
Book books[]; books = new Book[ numberElements ];
b.
Book books[]; books = new Book()[ numberElements ];
c.
new Book() books[]; books = new Book[ numberElements ];
d. All of the above.
CPSC150 EH17
2
Q3: Assume array items contains the values 0, 2, 4, 6 and 8. Which of the following set of statements uses the enhanced for loop to display each value in array items? a.
for ( int i = 0; i < items.length; i++ ) System.out.prinf( "%d\n", items[ i ] );
b.
for ( int i : items ) System.out.prinf( "%d\n", items[ i ] );
c.
for ( int i : items ) System.out.prinf( "%d\n", i );
d.
for ( int i = 0 : items.length ) System.out.prinf( "%d\n", items[ i ] );
Q4: Which statement correctly passes array items to method takeArray? Array items contains 10 elements. a. takeArray( items[] ). b. takeArray( items ). c. takeArray( items[ ] 9 ). d. Arrays cannot be passed to methods--each item must be sent to the method separately. Q5: Consider array items, which contains the values 0, 2, 4, 6 and 8. If method changeArray is called with the method call changeArray( items, items[ 2 ] ), what values are stored in items after the method has finished executing?
public static void changeArray( int passedArray[], int value ) { passedArray[ value ] = 12; value = 5; } // end method changeArray
a. 0, 2, 5, 6, 12. b. 0, 2, 12, 6, 8. c. 0, 2, 4, 6, 5. d. 0, 2, 4, 6, 12.
CPSC150 EH17
3
Q6: Write an application to simulate the rolling of two dice. The applicationshould use an object of class Random once to roll the first die and again to roll the second die. The sum of the two values should then be calculated. Each die can show an integer value from 1 to 6, sothe sum of the values will vary from 2 to 12, which 7 being the most frequent sum and 2 and 12 beingthe least frequent sums. The following figure shows the 36 possible combinations of the two dice. Your application should roll the dice 36,000 times. Use a one-dimensional array to tally the number of times each possible sum appears. Display the results in tabular format. Determine whether the totals are reasonable (e.g., there are six way to roll a 7, so approximately one-sixth of the rolls should be 7). 1 2 3 4 5 6 7 2 3 4 5 6 7 8 3 4 5 6 7 8 9 4 5 6 7 8 9 10 5 6 7 8 9 10 11 6 7 8 9 10 11 12
1 2 3 4 5 6