Exam 18: Generic Classes

Consider the following code snippet: Public static void reverse(List list) { . . . } Which of the following statements about this code is correct?

Which argument type cannot passed to generic methods? I Object II GUI components III primitive

Consider the following code snippet: Public class Box<E> { Private E data; Public Box(){ . . . } Public void insert(E value) { . . . } Public E getData() { . . . } } What will result from executing the following code? Box<String> box = new Box<String>(); ) . . Box)insert("blue Box"); String b = (String) box.getData();

The type variables in HashMap<K, V> in the standard library mnemonically represent ____.

What does the following code snippet mean: <E extends Comparable<E> & Measurable>

To maintain compatibility with pre-generic Java, type parameters are replaced by ordinary types called ____.

Select the correct header for this generic print method. Public static void print(E[] a) { For (int i = 0; i < a.length; i++) { System.out.println(a[i] + " "); } }

Given the following declaration, what is the type parameter in Stack<E> replaced with? Private Stack myStack = new Stack();

An inner helper class, such as a TreeNode inside the generic BinaryTree class, must meet which of the following criteria? I be public II be private III be declared as generic

Consider the following code snippet: Public static void reverse(List list) { . . . } Which of the following statements about this code is correct?

Consider the following code snippet: ArrayList<BankAccount> accounts1 = new ArrayList<BankAccount>(); //Line 1 LinkedList accounts2 = new LinkedList(); //Line 2 Accounts1.add("my Salary"); //Line 3 Accounts2.addFirst("my Salary"); //Line 4 Which of the above lines will cause a compile-time error?

Given the following generic method, which of the following CANNOT be the return type? Public static <E extends Comparable> E max(E[] a) { . . .} I String II Integer III double

Generics limit Java code somewhat. Which of the following are limitations of generic code? I cannot declare static variables of a generic type II cannot declare static methods of a generic type III cannot declare static inner classes of a generic type

Determine the output of the MyLinkedList generic class code below when the main method executes. Public class MyLinkedList<E> { Private MyNode first; Public MyLinkedList(E

Which of these Java library classes are implemented using type variables? I HashMap II LinkedList III ArrayList

Determine the correctness of the MyLinkedList generic class code below. Public class MyLinkedList<E> { Private MyNode first; Public E getFirst() { return first.data; } Private class MyNode { Private E data; Private MyNode next; } }

What is known for certain about a type parameter when a method constrains it as follows? <E extends MouseListener & MouseMotionListener>

Consider the following code snippet: ArrayList<Double> arr = new ArrayList<Double>(); String element = arr.get(0); Is there an error in this code?

Which of the following is not a wildcard type?

Consider the following code snippet: Public class LinkedList<E> { Private static E defaultValue; //Line 1 Public void add(E value, int n) { . . . } //Line 2 Private class Node { public String data; public Node next;)//Line 3 ) . . } What is wrong with this code?