Exam 15: The Java Collections Framework

A collection without an intrinsic order is called a ____.

Select an appropriate expression to complete the method below, which is designed to print the element at the bottom of a Stack collection. The contents of the original stack are restored before the method terminates. It is safe to assume that the original stack contains at least one element. public static void printBottom(Stack<String> theStack) { Stack<String> anotherStack = new Stack<String>(); While (theStack.size() > 0) { AnotherStack.push(theStack.pop()); } ____________________________ While (anotherStack.size() > 0) { TheStack.push(anotherStack.pop()); } }

Which of the following statements about a priority queue structure is correct?

Select an appropriate expression to complete the method below. The method should return the number of times that the string stored in name appears in theList. public static int count(LinkedList<String> theList, String name) { Int number = 0; Iterator<String> iter = theList.iterator(); While (______________________) { If (iter.next().equals(name)) { Number++; } } Return number; }

Consider the following code snippet: Stack<String> stringStack = new Stack<String>(); StringStack.push("ab"); StringStack.push("abc"); StringStack.push("a"); While (stringStack.size() > 0) { System.out.print(stringStack.pop() + ","); } What output will be produced when this code is executed?

Consider the following code snippet: LinkedList<String> words = new LinkedList<String>(); Words.addLast("abc"); Words.addLast("def"); Words.addLast("ghi"); System.out.print(words.removeLast()); System.out.print(words.removeFirst()); System.out.print(words.removeLast()); What will this code print when it is executed?

Which of the following statements about manipulating objects in a set is correct?

Which operations from the list data structure could be used to implement the push and pop operations of a stack data structure? I addLast II addFirst III removeFirst

Which Java package contains the LinkedList class?

Which method is NOT part of the ListIterator generic class?

An Undo feature in a word processor program that allows you to reverse a previously completed command is probably implemented using which structure type?

A linked list allows ____ access, but you need to ask the list for an iterator.

Select an appropriate expression to complete the following code segment, which is designed to print a message if the string stored in name is the first element of the players linked list. LinkedList<String> players = new LinkedList<String>(); // code to add elements to the linked list If ______________________________________ System.out.print(name + " is the first player on the list.");

Assume that you have declared a stack named myStack to hold String elements. Which of the following statements will correctly retrieve the top element from myStack without removing it?

What can a generic class be parameterized for?

Suppose we create a deque (double-ended queue) data structure. It is basically a queue, with its addLast and removeFirst operations, but we also add the addFirst and removeLast operations. If a line at the grocery store resembles a deque more than a queue, what is the most likely reason? I the cashier is very fast II the line is very long III the cashier is very slow

Consider the following code snippet: Stack<String> words1 = new Stack<String>(); ArrayList<String> words3 = new ArrayList<String>(); Words1.push("abc"); Words1.push("def"); Words1.push("ghi"); While (!words1.empty()) { Words3.add(words1.pop()); } Int i = words3.size() - 1; While (i >= 0) { System.out.print(words3.remove(i)); I--; } What will this code print when it is executed?

Select an appropriate expression to complete the following method, which is designed to return the sum of the two smallest values in the parameter array numbers. public static int sumTwoLowestElements(int[] numbers) { PriorityQueue<Integer> values = new PriorityQueue<Integer>(); For (int num: numbers) { Values.add(num); } ______________________ }

What type of access does a LinkedList provide for its elements?

You have decided to store objects of a class in a TreeSet structure. Which of the following statements is correct?