OCA Exam Prep 1: Java Basic

Which of the following are valid Java identifiers? (Choose all that apply)

• A$B

• _helloWorld

• True

• java.lang

• Public

What is the output of the following program?

• Line 6 generates a compiler error.

• Line 7 generates a compiler error.

• Empty = false, Brand =

• Empty = false, Brand = null

• Empty = null, Brand = null

Which of the following are true? (Choose all that apply)

• Line 5 generates a compiler error.

• Line 7 generates a compiler error.

• Line 9 generates a compiler error.

• Line 8 generates a compiler error.

• Line 6 generates a compiler error.

Given the following class, which of the following is true? (Choose all that apply)

• If String result = "done"; is inserted on line 2, the code will compile.

• If String result = "done"; is inserted on line 6, the code will compile.

• If String result = "done"; is inserted on line 4, the code will compile.

• If String result = "done"; is inserted on line 9, the code will compile.

Given the following classes, which of the following can independently replace INSERT IMPORTS HERE to make the code compile? (Choose all that apply)

• import aquarium.*;

• import aquarium.*.Jelly;

• import aquarium.jellies.Jelly;

• import aquarium.jellies.*;

• import aquarium.jellies.Jelly.*;

Given the following classes, what is the maximum number of imports that can be removed and have the code still compile?

• 0

• 1

• 2

• 3

• 4

Given the following classes, which of the following snippets can be inserted in place of INSERT IMPORTS HERE and have the code compile? (Choose all that apply)

• import aquarium.*;

• import aquarium.Water;

  import aquarium.jellies.*;

• import aquarium.*;

  import aquarium.jellies.Water;

• import aquarium.*;

  import aquarium.jellies.*;

• import aquarium.Water;

  import aquarium.jellies.Water;

Given the following class, which of the following calls print out Blue Jay? (Choose all that apply)

• java BirdDisplay Sparrow Blue Jay

• java BirdDisplay Sparrow "Blue Jay"

• java BirdDisplay Blue Jay Sparrow

• java BirdDisplay "Blue Jay" Sparrow

• java BirdDisplay.class Sparrow "Blue Jay"

Which of the following legally fill in the blank so you can run the main() method from the command line? (Choose all that apply)

• String[] _names

• String[] 123

• String abc[]

• String _Names[]

• String... $n

Which of the following are legal entry point methods that can be run from the command line? (Choose all that apply)

• private static void main(String[] args)

• public static final main(String[] args)

• public static void main(String[] args)

• public static void test(String[] args)

• public static main(String[] args)