1Z0-819 | Up To Date 1Z0-819 Exam Guide For Java SE 11 Developer Certification

NEW QUESTION 1
Which statement about a functional interface is true?

• A. It must be defined with the public access modifier.
• B. It must be annotated with @FunctionalInterface.
• C. It is declared with a single abstract method.
• D. It is declared with a single default method.
• E. It cannot have any private methods and static methods.

Answer: C

NEW QUESTION 2
Given these two classes:


And given this fragment:

Which describes the fragment?

• A. It throws IllegalMonitorStateException.
• B. It is subject to deadlock.
• C. It is subject to livelock.
• D. The code does not compile.

Answer: D

NEW QUESTION 3
Given:

What is the result?

• A. null
• B. nothing
• C. It fails to compile.
• D. java.lang.IllegalAccessException is thrown.
• E. Student

Answer: C

NEW QUESTION 4
Which two safely validate inputs? (Choose two.)

• A. Delegate numeric range checking of values to the database.
• B. Accept only valid characters and input values.
• C. Use trusted domain-specific libraries to validate inputs.
• D. Assume inputs have already been validated.
• E. Modify the input values, as needed, to pass validation.

Answer: AB

NEW QUESTION 5
Which interface in the java.util.function package will return a void return type?

• A. Supplier
• B. Predicate
• C. Function
• D. Consumer

Answer: D

NEW QUESTION 6
Given the code fragment:
Path currentFile = Paths.get(“/scratch/exam/temp.txt”); Path outputFile = Paths get(“/scratch/exam/new.txt”); Path directory = Paths.get(“/scratch/”); Files.copy(currentFile, outputFile); Files.copy(outputFile, directory);
Files.delete (outputFile);
The /scratch/exam/temp.txt file exists. The /scratch/exam/new.txt and /scratch/new.txt files do not exist. What is the result?

• A. /scratch/exam/new.txt and /scratch/new.txt are deleted.
• B. The program throws a FileaAlreadyExistsException.
• C. The program throws a NoSuchFileException.
• D. A copy of /scratch/exam/new.txt exists in the /scratch directory and /scratch/exam/new.txt is deleted.

Answer: C

Explanation:

NEW QUESTION 7
Given:

What is the result?

• A. is it 1
• B. An IndexOutOfBoundsException is thrown at runtime.
• C. is it 0
• D. this is it 2
• E. this is it 3

Answer: D

Explanation:

NEW QUESTION 8
Given:

What is the result?

• A. A ClassCastException is thrown at runtime.
• B. AnotherClass#methodA()AnotherClass#methodA()
• C. The compilation fails.
• D. SomeClass#methodA()AnotherClass#methodA()
• E. AnotherClass#methodA()SomeClass#methodA()
• F. SomeClass#methodA()SomeClass#methodA()

Answer: C

Explanation:

NEW QUESTION 9
Given:

What is the result?

• A. b1
• B. 2
• C. b2
• D. 1
• E. b3
• F. 3
• G. The compilation fails due to an error in line 1.

Answer: F

Explanation:

NEW QUESTION 10
Given:

Which two changes need to be made to make this class compile? (Choose two.)

• A. Change Line 1 to an abstract class:public abstract class API {
• B. Change Line 2 access modifier to protected:protected void checkValue(Object value)throws IllegalArgumentException;
• C. Change Line 1 to a class:public class API {
• D. Change Line 1 to extend java.lang.AutoCloseable:public interface API extends AutoCloseable {
• E. Change Line 2 to an abstract method:public abstract void checkValue(Object value)throws IllegalArgumentException;

Answer: CE

NEW QUESTION 11
Given:

Assume the file on path does not exist. What is the result?

• A. The compilation fails.
• B. /u01/work/filestore.txt is not deleted.
• C. Exception
• D. /u01/work/filestore.txt is deleted.

Answer: A

Explanation:

NEW QUESTION 12
Given:

Which is true about line 1?

• A. If the value is not present, a NoSuchElementException is thrown at run time.
• B. It always executes the System.out::print statement.
• C. If the value is not present, a NullPointerException is thrown at run time.
• D. If the value is not present, nothing is done.

Answer: D

Explanation:

NEW QUESTION 13
Which two describe reasons to modularize the JDK? (Choose two.)

• A. easier to understand the Java language
• B. improves security and maintainability
• C. easier to expose implementation details
• D. improves application robustness
• E. easier to build a custom runtime linking application modules and JDK modules

Answer: BD

NEW QUESTION 14
Given:

Which three classes successfully override printOne()? (Choose three.)

• A. Option A
• B. Option B
• C. Option C
• D. Option D
• E. Option E
• F. Option F

Answer: ACD

NEW QUESTION 15
Given the code fragment:

What is the result?

• A. ab cd ef
• B. An ArrayIndexOutOfBoundsException is thrown at runtime.
• C. The compilation fails.
• D. abc def
• E. ad be cf

Answer: E

NEW QUESTION 16
Given:

Which two statements are true if the method is added to Bar? (Choose two.)

• A. public Collection<String> foo(Collection<String> arg) { ... } overrides Foo.foo.
• B. public <T> Collection<T> foo(Stream<T> arg) { ... } overloads Foo.foo.
• C. public <T> List<T> foo(Collection<T> arg) { ... } overrides Foo.foo.
• D. public <T> Collection<T> foo(Collection<T> arg) { ... } overloads Foo.foo.
• E. public <T> Collection<T> bar(Collection<T> arg) { ... } overloads Foo.foo.
• F. public <T> Iterable<T> foo(Collection<T> arg) { ... } overrides Foo.foo.

Answer: CF

NEW QUESTION 17
Given:

What is the output?

• A. Hello world!Bonjour le monde!
• B. Hello world!Hello world!
• C. Bonjour le monde!Hello world!
• D. Bonjour le monde!Bonjour le monde!

Answer: C

Explanation:

NEW QUESTION 18
Given:

Which two lines of code when inserted in line 1 correctly modifies instance variables? (Choose two.)

• A. setCCount(c) = cCount;
• B. tCount = tCount;
• C. setGCount(g);
• D. cCount = setCCount(c);
• E. aCount = a;

Answer: BE

NEW QUESTION 19
Given:

executed with this command: java Main one two three What is the result?

• A. 0). one
• B. 0). one1). two2). three
• C. The compilation fails.
• D. It creates an infinite loop printing:0). one1). two1). two...
• E. A java.lang.NullPointerException is thrown.

Answer: D

NEW QUESTION 20
Which two commands are used to identify class and module dependencies? (Choose two.)

• A. jmod describe
• B. java Hello.java
• C. jdeps --list-deps
• D. jar --show-module-resolution
• E. java --show-module-resolution

Answer: CE

NEW QUESTION 21
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