Testaufgabe für eines der großen IT-Unternehmen in Weißrussland

Hallo zusammen! Wie im Kommentar zum letzten Artikel versprochen , veröffentliche ich eine Testaufgabe zu J2SE und JavaEE, die mir zur Einschreibung für ein Praktikum zugesandt wurde. Für die Bearbeitung haben Sie 30 Minuten Zeit. Es stimmt, ich habe es geschafft, 12 von 14 Fragen zu speichern. - bedeutet, dass es mehrere Antwortmöglichkeiten geben kann. * bedeutet, dass es nur eine Antwortmöglichkeit geben kann

1. Frage
Integer a = new Integer(2); Integer b = new Integer(2); What code will provide output: "false"? Check all that apply. Варианты ответов: - System.out.println(a.intValue() == b.intValue()); - System.out.println(a.compareTo(b)); - System.out.println(a.equals(b)); - System.out.println(a == b);
2. Frage
Which HTTP methods are NOT considered idempotent (multiple execution of query will give the same result)? (Choose all that apply) Варианты ответов: - GET - POST - HEAD - PUT
3. Frage
How should servlet developers handle the HttpServlet's service() method when extending HttpServlet? (Choose all that apply). Варианты ответов: - They should override the service() method in most cases. - They should call the service() method from doGet() or doPost(). - They should call the service() method from the init() method. - They should override at least one doXXX() method (such as doPost()).
4. Frage
Which methods are used by a servlet to handle form data from a client? (Choose all that apply) Варианты ответов: - HttpServlet.doHead() - HttpServlet.doPost() - HttpServlet.doForm() - ServletRequest.doGet() - ServletRequest.doPost() - ServletRequest.doForm()
5. Frage
Given the Product Bean: public class Product{ public Product(String title, int size){ this.title = title; this.size = size; } String title; int size; } How would servlet code from a service method (e.g. doPost()) pass a Product bean info to the jsp? Варианты ответов: * response.setAttribute("product", new Product("Shirt", t)); * response.setParameter("product", new Product("Shirt", t)); * request.setAttribute("product", new Product("Shirt", t)); * request.setParameter("product", new Product("Shirt", t));
6. Frage
You have to create your own type of exception, named UserOperationExсeption. And you need to make it a checked exсepetion. What is the appropriate signature in this case? Check all that apply. Варианты ответов: - public class UserOperationExсeption extends RuntimeExсeption{...} - public class UserOperationExсeption extends Exсeption{...} - public class UserOperationExсeption extends IOExсeption{...} - public class UserOperationExсeption extends extends Error{...}
7. Frage
Given following classes hierarchy: public class Building {...} public class Warehouse extends Building {...} public class Shop extends Building {...} public class SportsShop extends Shop {...} and code: ... Building b1 = new Building(); Building b2 = new Warehouse(); ... What code will cause a ClassCastException to be thrown? Check all that apply. Варианты ответов: - Warehouse w1 = b2; - Warehouse w2 = (Warehouse) b2; - Warehouse w3 = new SportsShop(); - Shop s1 = (Shop)b1; - Shop s2 = new SportsShop();
8. Frage
Given the method: public int shift(int value, int offset) { value += offset; return value; } What will be the output of following code: int v = 2; shift(v,5); System.out.println(v); Варианты ответов: * 2 * 5 * 7 * 3
9. Frage
Given: public class Product { public Product(String title, int size){ this.title = title; this.size = size; } String title; int size; public String toString() { return title + ":" + size; } } ... Set products = new HashSet(); products.add(new Product("Hat", 3)); products.add(new Product("Hat", 3)); System.out.println(products); What items will be in the programm output, considering that Product class inherits equals() and hashCode() methods from Object? Варианты ответов: * Hat * [Hat:3, Hat:3] * [Hat:3] * RuntimeException about duplicate elements
10. Frage
What code is valid for creating immutable list? Варианты ответов: * List immutableItems = Collections.unmodifiableList(new ArrayList()); immutableItems.add("i1"); immutableItems.add("i2"); * List items = new ArrayList(); items.add("i1); items.add("i2"); List immutableItems = Collections.unmodifiableList(items); * List items = new ArrayList(); items.add("i1); items.add("i2"); final List immutableItems = items; * List can't be immutable
11. Frage
What is complexity (Big 0 notation) of ArrayList contains() method? Варианты ответов: * 0(n^2) * 0(log(n)) * 0(n) * 0(1)
12. Frage
Given and array of size n, suppose you need to write a program that calculates the sum of every second element of this array. What will be the complexity (Big 0 notation) of most optimal implementation of this algorithm? Варианты ответов: * 0(n^2) * 0(n/2) * 0(n) * 0(1)

Ich schlage vor, zu diskutieren, welche Antwortoptionen richtig sind.