Question 41
Given:
class Student {
String course, name, city;
public Student (String name, String course, String city) {
this.course = course; this.name = name; this.city = city;
}
public String toString() {
return course + ":" + name + ":" + city;
}
and the code fragment:
List<Student> stds = Arrays.asList(
new Student ("Jessy", "Java ME", "Chicago"),
new Student ("Helen", "Java EE", "Houston"),
new Student ("Mark", "Java ME", "Chicago"));
stds.stream()
. collect(Collectors.groupingBy(Student::getCourse))
. forEach(src, res) -> System.out.println(scr));
What is the result?
class Student {
String course, name, city;
public Student (String name, String course, String city) {
this.course = course; this.name = name; this.city = city;
}
public String toString() {
return course + ":" + name + ":" + city;
}
and the code fragment:
List<Student> stds = Arrays.asList(
new Student ("Jessy", "Java ME", "Chicago"),
new Student ("Helen", "Java EE", "Houston"),
new Student ("Mark", "Java ME", "Chicago"));
stds.stream()
. collect(Collectors.groupingBy(Student::getCourse))
. forEach(src, res) -> System.out.println(scr));
What is the result?
Question 42
Given the code fragment:
class CallerThread implements Callable<String> {
String str;
public CallerThread(String s) {this.str=s;}
public String call() throws Exception {
return str.concat("Call");
}
}
and
public static void main (String[] args) throws InterruptedException, ExecutionException
{
ExecutorService es = Executors.newFixedThreadPool(4); //line n1
Future f1 = es.submit (newCallerThread("Call"));
String str = f1.get().toString();
System.out.println(str);
}
Which statement is true?
class CallerThread implements Callable<String> {
String str;
public CallerThread(String s) {this.str=s;}
public String call() throws Exception {
return str.concat("Call");
}
}
and
public static void main (String[] args) throws InterruptedException, ExecutionException
{
ExecutorService es = Executors.newFixedThreadPool(4); //line n1
Future f1 = es.submit (newCallerThread("Call"));
String str = f1.get().toString();
System.out.println(str);
}
Which statement is true?
Question 43
Given:
public interface Moveable<Integer> {
public default void walk (Integer distance) {System.out.println("Walking");) public void run(Integer distance);
}
Which statement is true?
public interface Moveable<Integer> {
public default void walk (Integer distance) {System.out.println("Walking");) public void run(Integer distance);
}
Which statement is true?
Question 44
Given:
public class Emp {
String fName;
String lName;
public Emp (String fn, String ln) {
fName = fn;
lName = ln;
}
public String getfName() { return fName; }
public String getlName() { return lName; }
}
and the code fragment:
List<Emp> emp = Arrays.asList (
new Emp (“John”, “Smith”),
new Emp (“Peter”, “Sam”),
new Emp (“Thomas”, “Wale”));
emp.stream()
//line n1
.collect(Collectors.toList());
Which code fragment, when inserted at line n1, sorts the employees list in descending order of fNameand then ascending order of lName?
.sorted (Comparator.comparing(Emp::getfName).reserved().thenComparing
public class Emp {
String fName;
String lName;
public Emp (String fn, String ln) {
fName = fn;
lName = ln;
}
public String getfName() { return fName; }
public String getlName() { return lName; }
}
and the code fragment:
List<Emp> emp = Arrays.asList (
new Emp (“John”, “Smith”),
new Emp (“Peter”, “Sam”),
new Emp (“Thomas”, “Wale”));
emp.stream()
//line n1
.collect(Collectors.toList());
Which code fragment, when inserted at line n1, sorts the employees list in descending order of fNameand then ascending order of lName?
.sorted (Comparator.comparing(Emp::getfName).reserved().thenComparing
Question 45
Given the definition of the Country class:
public class country {
public enum Continent {ASIA, EUROPE}
String name;
Continent region;
public Country (String na, Continent reg) {
name = na, region = reg;
}
public String getName () {return name;}
public Continent getRegion () {return region;}
}
and the code fragment:
List<Country> couList = Arrays.asList (
new Country ("Japan", Country.Continent.ASIA),
new Country ("Italy", Country.Continent.EUROPE),
new Country ("Germany", Country.Continent.EUROPE));
Map<Country.Continent, List<String>> regionNames = couList.stream ()
.collect(Collectors.groupingBy (Country ::getRegion,
Collectors.mapping(Country::getName, Collectors.toList()))));
System.out.println(regionNames);
What is the output?
public class country {
public enum Continent {ASIA, EUROPE}
String name;
Continent region;
public Country (String na, Continent reg) {
name = na, region = reg;
}
public String getName () {return name;}
public Continent getRegion () {return region;}
}
and the code fragment:
List<Country> couList = Arrays.asList (
new Country ("Japan", Country.Continent.ASIA),
new Country ("Italy", Country.Continent.EUROPE),
new Country ("Germany", Country.Continent.EUROPE));
Map<Country.Continent, List<String>> regionNames = couList.stream ()
.collect(Collectors.groupingBy (Country ::getRegion,
Collectors.mapping(Country::getName, Collectors.toList()))));
System.out.println(regionNames);
What is the output?