Application Programming final review (CS 3443)

Consider the following lines of code public class Promotion { public static void main(String args[]) { int i = 5; float f = 5.5f; double d = 3.8; char c = 'a'; if (i == f) c++; if(((int) (f+d)) == ((int) f + (int) d )) c +=2; System.out.println(c); } } A. The code will fail to compile B. It will print a C. It will print b D. It will print c

B

What will the following code output? import java.util.*; import java.io.IOException; class A { public static void main(String[] args) { List<String> color = new ArrayList<String>(Arrays.asList("blue", "red", "yellow", "orange")); color.add(2, "pink"); System.out.println(color); } } A. [blue, red, pink, orange] B. [blue, red, pink, yellow, orange] C. [blue, pink, yellow, orange] D. [blue, red, yellow, pink, orange]

B

Which of the following modifiers is used as a substitute for multiple inheritance in Java? A. Abstract B. Interface C. public D. protected

B

How do you model the following situation with a UML class diagram: A fair is visited by at least one visitor. One visitor visits at least one fair. A. [Visitor] 1..* ------- * [Fair] B. [Visitor] 1 ------- 1* [Fair] C. [Visitor] 1..* ------- 1..* [Fair] D. [Visitor] * ------- * [Fair]

C

java.util.Collections is a

Class

Errors

Compilation issues, often caused by invalid syntax

Anonymous inner class

Constructs a new object of a new class, declared without a name

What will the following code print? class Base { public void show() { System.out.println("Base::show() called"); } } class Derived extends Base { public void show() { System.out.println("Derived::show() called"); } } class Main { public static void main(String[] args) { Base b = new Derived(); b.show; } }

Derived::show() called

MVC

Design pattern which separates the UI from the application data

Single Responsibility

Design principle: a class should have only one responsibility

Interface Segregation

Design principle: clients should not be forced to depend on interfaces they do not use

Dependency Inversion

Design principle: high level modules should not depend on low level modules - both should depend on abstraction.

Liskov Substitution

Design principle: objects should be replaceable with instance of their subclasses

Open-Closed

Design principle: software should be open for extension & closed to modification.

What will the following code print? final class Base { public void show() { System.out.println("Base::show() called"); } } class Derived extends Base { public void show() { System.out.println("Derived::show() called"); } } class Main { public static void main(String[] args) { Base b = new Derived(); b.show; } }

Error: final cannot be overridden

What will the following code print when compiled and run? class Grandparent { public void Print() { System.out.println("Grandparent's Print()"); } } class Parent extends Grandparent { public void Print() { System.out.println("Parent's Print()"); } } class Child extends Parent { public void Print() { super.super.Print(); system.out.println("Child's Print()"); } } public class Main { public static void main(String[] args) { Child c = new Child(); c.Print(); } }

Error: super.super is not supported

To create a GUI using JavaFX, "JavaFX" class must be extended?

False

True or False Functional interfaces can have more than one abstract method

False

True or False Java Abstract Window Type (AWT) follows the Model View Controller (MVC) architectural pattern.

False

True or False Open closed principle says that: "Objects in a program should be replaceable with instance of their subtypes without altering the correctness of that program"

False

True or False The comparable interface in Java facilitates comparisons between objects and can compare two objects of two different classes.

False

True or False The compiler converts the source code line-by-line during run time

False

True or False class Test { public static void main(String[] args) { short s = 10; // 1 char c = s; // 2 s = c; // 3 } } Both lines 2 and 3 are valid?

False

Lambda expression type that accepts an integer and returns an integer

Function

Which of the following collection is not of Iterable type?

HashMap

Which of the following implementation will you use if you were to insert elements at any position in the collection?

LinkedList

What will the following code print when compiled and run? public class Paper { public String title; public int id; public Paper(String title, int id) { this.title = title; this.id = id; } public static void main(String[] args) { Paper[] papers = { new Paper("T1", 1), new Paper("T2", 2), new Paper("T3", 3) }; System.out.println(papers); System.out.println(papers[1]); System.out.println(papers[1].id); } }

Paper;@hashcode Paper@hashcode 2

Inheritance

Paradigm enabling subclass/superclass relationship

What will the following code print when compiled and run? class Grandparent { public void Print() { System.out.println("Grandparent's Print()"); } } class Parent extends Grandparent { public void Print() { System.out.println("Parent's Print()"); } } class Child extends Parent { public void Print() { super.Print(); system.out.println("Child's Print()"); } } public class Main { public static void main(String[] args) { Child c = new Child(); c.Print(); } }

Parent print() Child print()

Lambda expression type that accepts an integer and returns a boolean

Predicate

What will the following code print when compiled and run? import java.util.Scanner; import java.io.PrintWriter; import java.io.StringWriter; public class StringOutputStresm { public static void main(String[] args) { String item; int quantity; int discount; StringWriter itemCharStream = new StringWriter(); PrintWriter itemOSS = new PrintWriter(itemCharStream); item = "Shoes"; quantity = 12; discount = 25; itemOSS.println(item + " x" + quantity); itemOSS.print(discount + "% off"); System.our.print(itemCharStream.toString()); } }

Shoes x12 25% off

Subclass

The "child" class which may inherit methods from another class

Superclass

The "parent" class which may define methods to be inherited

True or False Open closed principle says that: "Objects in a program should be open to extension but closed to modification"

True

True or False The comparable interface in Java facilitates comparisons between objects and can compare the current object with another.

True

True or False The comparator interface in Java facilitates comparisons between objects and can compare two objects of two different classes.

True

True or False The compiler converts the source code in one go before run time

True

True or False The interpreter converts the source code line-by-line during run time

True

True or False The keyword static allows main() to be called without having to instantiate a particular instance of the class

True

True or False class Test { public static void main(String[] args) { short s = 10; // 1 char c = (char) s; // 2 s = c; // 3 } } Is line 2 valid?

True

Set

Type of data structure which contains no dublicates

List

Type of data structure which enables ordered organization

Map

Type of data structure which requires key/value pairs

Which of the following is true for the arguments in lambda expressions?

Type of the argument can be omitted

Yes or no What we call as JFrame in Swing is similar to Stage in JavaFX?

Yes

Shorter lambda expression that adds two numbers and return their sum

(a, b) -> a + b;

Longer lambda expression that adds two numbers and return their sum

(int a, int b) -> a + b;

What does this code output? public class Cat { public String name; public void parseName() { System.out.print("1"); try { System.out.print("2"); int x = Integer.parseInt(name); System.out.print("3"); } catch (NullPointerException e) { System.out.print("4"); } System.out.print("5"); } public static void main(String[] args) { Cat leo = new Cat(); leo.name = "Leo"; leo.parseName(); System.out.print("6"); } }

12 Error

The communication/wire between the scene builder and the controller class is done using the annotation?

@FXML

What is the return type of the equals() method of the Object class? A. boolean B. Object C. String D. Char

A

Which line of code will compile without RuntimeException? public interface Temperature { // 1 boolean hasScales(); // 2 public default getTempFahrenheit () { // 3 return 113.0; // 4 } public default void Scale(); // 5 public int getTempCelsius() { // 6 return 45; // 7 } } (hint 5 is correct) A. 2 B. 3 C. 6 D. 7

A

Abstract class

A Java class which cannot be instantiated, should be implemented

Collection

A framework that can hold groups of objects

Lambda expression

instances of functional interfaces

Create a Button called goButton with the label "Go!": Button goButton = ...

new Button("Go!");

The class name for the application should be SimpleDrawingAppFX

public class SimpleDrawingAppFX extends Application{

In the model view controller architectural pattern, the model corresponds to

source/storage

What is the name of the method that is used to start the execution of a thread?

start()

Given a Stage object named appStage, write a statement that sets the stage's title to "Employees".

appStage.setTitle("Employees");

Given a Stage object named appStage, write a statement that makes the stage visible.

appStage.show();