Suppose objects a and b are from a user-defined class that implements the Comparable interface.  What must be true about the return value of a.compareTo(b) for the compareTo method that this class implements?

Which sort algorithm starts by partitioning the array and selecting a pivot element?

The partial linear search method below is designed to search an array of String objects.  Select the expression that would be needed to complete the method. public static int search(String[] a, String item) { for(int i = 0; i < a.length; i++) { if ( ____________________________ ) { return i; } return -1; } }

Assuming that names is a Queue of String objects, select a statement to complete the code segment below.  The code is designed to remove the last element from the queue, which is guaranteed to have at least one element. Queue aQueue = new LinkedList(); while (names.size() > 1) { aQueue.add(names.remove()); } names.remove(); while (aQueue.size() > 0) { ____________________________ }

Assuming that names is a Queue of String objects, select a statement to complete the code segment below.  The code is designed to remove the last element from the queue, which is guaranteed to have at least one element. Queue aQueue = new LinkedList(); while (names.size() > 1) { aQueue.add(names.remove()); } names.remove(); while (aQueue.size() > 0) { ____________________________ }

Consider the following code snippet which is supposed to show the total order amount when the button is clicked: public static void main(String[] args) { final Order myOrder = new Order(); JButton button = new JButton(“Calculate”); final JLabel label = new JLabel(“Total amount due”); . . . class MyListener implements ActionListener { public void actionPerformed(ActionEvent event) { label.setText(“Total amount due ” + myOrder.getAmountDue()); } } ActionListener listener = new MyListener(); } What is wrong with this code?

Which data structure would best be used for keeping track of groceries to be purchased at the food market?

Consider the following code snippet: public class Coin { private String name; . . . public boolean equals(Object otherCoin) { return name.equals(otherCoin.name); } . . . } What is wrong with this code?

Assume inputFile is a Scanner object used to read data from a text file that contains a series of double values. Select an expression to complete the following code segment, which reads the values and prints them in standard output, one per line, in a field 15 characters wide, with two digits after the decimal point. while (inputFile.hasNextDouble()) { double value = inputFile.nextDouble(); ___________________________________ // statement to display double value }

What reserved word in a method definition ensures that subclasses cannot override the method?