1Z0-811 Object-Oriented Programming — All Questions With Answers

Refer to the exhibit.
interface Printable {
    default void print() { System.out.println("Printable"); }
}
interface Showable {
    default void print() { System.out.println("Showable"); }
}
class Document implements Printable, Showable {
    // no override
}

Refer to the exhibit.
public class Employee {
    private String name;
    public Employee(String name) { this.name = name; }
    public String getName() { return name; }
}
public class Manager extends Employee {
    private int teamSize;
    public Manager(String name, int teamSize) {
        super(name);
        this.teamSize = teamSize;
    }
}

public class Vehicle { protected int speed; public Vehicle() { speed = 0; } public void accelerate() { speed += 10; } } public class Car extends Vehicle { public void accelerate() { speed += 20; } }

public class Test { public static void main(String[] args) { Animal a = new Animal(); a.sound(); } } abstract class Animal { abstract void sound(); }

public class Singleton { private static Singleton instance; private Singleton() {} public static Singleton getInstance() { if (instance == null) { instance = new Singleton(); } return instance; } }

class Vehicle {
    String type = "Vehicle";
}
class Car extends Vehicle {
    String type = "Car";
}
public class Test {
    public static void main(String[] args) {
        Vehicle v = new Car();
        System.out.println(v.type);
    }
}

interface Printable {
    void print();
}
class Document implements Printable {
    public void print() { System.out.println("Document"); }
}
class Photo extends Document {
    public void print() { System.out.println("Photo"); }
}
public class Test {
    public static void main(String[] args) {
        Document d = new Photo();
        d.print();
    }
}

javac Test.java
Test.java:5: error: cannot find symbol
    System.out.println(value);
                        ^
  symbol:   variable value
  location: class Test

Consider the following Java class:

public class Employee {
    private String name;
    public Employee(String name) {
        name = name;
    }
    public String getName() {
        return name;
    }
}

class Animal {
    public void sound() {
        System.out.println("Animal sound");
    }
}
class Dog extends Animal {
    public void sound() {
        System.out.println("Bark");
    }
    public void fetch() {
        System.out.println("Fetching");
    }
}
public class Test {
    public static void main(String[] args) {
        Animal a = new Dog();
        a.sound();
        ((Dog) a).fetch();
    }
}