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A palindrome is a word or phrase that reads the same forward or backward. Consider the following code snippet: public boolean palindrome(String string) { return isPal(string, 0, string.length() – 1); } private boolean isPal(String string, int left, int right) { if (left >= right) { return true; } else if (string.charAt(left) == string.charAt(right)) { return isPal(string, left + 1, right – 1); } else { return false; } } What is the purpose of the palindrome method?

If the user wants to process keystrokes, which methods of the KeyListener interface must be implemented?

A portion of your program includes the loops shown in the code snippet below to examine the elements of two arrays, arr1 and arr2, both of length n: int matches = 0; for (int i = 0; i < arr1.length; i++) { for (int j = 0; j < arr2.length; j++) { if (arr1[i].equals(arr2[j])) { matches++; } } } What can you conclude about the running time of this section of code?

If you have multiple classes in your program that have implemented the same interface in different ways, how is the correct method executed?

Suppose you wish to implement the Comparable interface to allow your Vehicle class to compare Auto objects only. Which of the following is the correct way to do this?

Suppose a developer gets class XYZ files and documentation from a subcontractor. This class does not implement the Comparable interface. What must be true in order for the developer to sort an array of XYZ objects without modifying the XYZ class?

In Java, if you forget to call a superclass constructor explicitly in the constructor of a subclass, what will happen?

Suppose you wish to implement the Comparable interface to allow your Vehicle class to compare Auto objects only. Which of the following is the correct way to do this?

The method below implements the exponentiation operation recursively by taking advantage of the fact that, if the exponent n is even, then xn = (x n/2)2. Select the expression that should be used to complete the method so that it computes the result correctly. public static double power(double base, int exponent) { if (exponent % 2 != 0) // if exponent is odd { return base * power(base, exponent – 1); } else if (exponent > 0) { double temp = ________________________ ; return temp * temp; } return base; }

Which of the following is an event source?