Bài kiểm tra cho một trong những công ty CNTT lớn ở Belarus

Chào mọi người! Như tôi đã hứa trong phần bình luận của bài viết trước , tôi đang đăng một bài kiểm tra về J2SE và JavaEE đã được gửi cho tôi để đăng ký thực tập. Bạn có 30 phút để hoàn thành nó. Đúng vậy, tôi đã lưu được 12 trong số 14 câu hỏi. - nghĩa là có thể có nhiều phương án trả lời * nghĩa là chỉ có một phương án trả lời

1. Câu hỏi
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. Câu hỏi
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. Câu hỏi
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. Câu hỏi
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. Câu hỏi
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. Câu hỏi
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. Câu hỏi
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. Câu hỏi
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. Câu hỏi
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. Câu hỏi
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. Câu hỏi
What is complexity (Big 0 notation) of ArrayList contains() method? Варианты ответов: * 0(n^2) * 0(log(n)) * 0(n) * 0(1)
12. Câu hỏi
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)

Tôi đề nghị thảo luận về những lựa chọn trả lời nào là đúng.