Review Questions 3  – Building Blocks – 1Z0-829 Study Guide

1. Which are true about this code? (Choose all that apply.)

var blocky = “””

squirrel \s

pigeon \

termite”””;

System.out.print(blocky);

1. It outputs two lines.

• It outputs three lines.

• It outputs four lines.

• There is one line with trailing whitespace.

• There are two lines with trailing whitespace.

• If we indented each line five characters, it would change the output.

1. What lines are printed by the following program? (Choose all that apply.)

1. public class WaterBottle {

• private String brand;

• private boolean empty;

• public static float code;

• public static void main(String[] args) {

• WaterBottle wb = new WaterBottle();

• System.out.println(“Empty = ” + wb.empty);

• System.out.println(“Brand = ” + wb.brand);

• System.out.println(“Code = ” + code);

1. } }

1. Line 8 generates a compiler error.

• Line 9 generates a compiler error.

• Empty =

• Empty = false

• Brand =

• Brand = null

• Code = 0.0

• Code = 0f

1. Which of the following statements about var are true? (Choose all that apply.)

1. A var can be used as a constructor parameter.

• The type of a var is known at compile time.

• A var cannot be used as an instance variable.

• A var can be used in a multiple variable assignment statement.

• The value of a var cannot change at runtime.

• The type of a var cannot change at runtime.

• The word var is a reserved word in Java.

1. Which are true about the following code? (Choose all that apply.)

var num1 = Long.parseLong(“100”); var num2 = Long.valueOf(“100”); System.out.println(Long.max(num1, num2));

1. The output is 100.

• The output is 200.

• The code does not compile.

• num1 is a primitive.

• num2 is a primitive.

• Which statements about the following class are correct? (Choose all that apply.)

1. public class PoliceBox {

• String color;

• long age;

• public void PoliceBox() {

• color = “blue”;

• age = 1200;

• }

• public static void main(String []time) {

• var p = new PoliceBox();

1. var q = new PoliceBox();

1. p.color = “green”;

1. p.age = 1400;

1. p = q;

1. System.out.println(“Q1=”+q.color);

1. System.out.println(“Q2=”+q.age);

1. System.out.println(“P1=”+p.color);

1. System.out.println(“P2=”+p.age);

1. } }

1. It prints Q1=blue.

• It prints Q2=1200.

• It prints P1=null.

• It prints P2=1400.

• Line 4 does not compile.

• Line 12 does not compile.

• Line 13 does not compile.

• None of the above.

• What is the output of executing the following class?

1. public class Salmon {

• int count;

• { System.out.print(count+”-­”); }

• { count++; }

• public Salmon() {

• count = 4;

• System.out.print(2+”-­”);

• }

• public static void main(String[] args) {

1. System.out.print(7+”-­”);

1. var s = new Salmon();

1. System.out.print(s.count+”-­”); } }

1. 7-0-2-1-

• 7-0-1-

• 0-7-2-1-

• 7-0-2-4-

• 0-7-1-

• The class does not compile because of line 3.

• The class does not compile because of line 4.

• None of the above.

• Given the following class, which of the following lines of code can independently replace INSERT CODE HERE to make the code compile? (Choose all that apply.)

public class Price {

public void admission() {

INSERT CODE HERE

System.out.print(amount);

} }

1. int Amount = 0b11;

• int amount = 9L;

• int amount = 0xE;

• int amount = 1_2.0;

• double amount = 1_0_.0;

• int amount = 0b101;

• double amount = 9_2.1_2;

• double amount = 1_2_.0_0;

• Which statements about the following class are true? (Choose all that apply.)

1. public class River {

• int Depth = 1;

• float temp = 50.0;

• public void flow() {

• for (int i = 0; i < 1; i++) {

• int depth = 2;

• depth++;

• temp-­-­;

• }

1. System.out.println(depth);

1. System.out.println(temp); }

1. public static void main(String… s) {

1. new River().flow();

1. } }

1. Line 3 generates a compiler error.

• Line 6 generates a compiler error.

• Line 7 generates a compiler error.

• Line 10 generates a compiler error.

• The program prints 3 on line 10.

• The program prints 4 on line 10.

• The program prints 50.0 on line 11.

• The program prints 49.0 on line 11.