The answer is that options A, B, and D are correct because an interface can contain default methods, static methods, and can extend multiple interfaces using the extends keyword. Since Java 8, interfaces have evolved beyond abstract contracts to include concrete method implementations: default methods allow adding new functionality without breaking existing implementations, while static methods provide utility functions scoped to the interface. This directly addresses the concept of interface default static methods multiple inheritance, which the Oracle Java Foundations 1Z0-811 exam tests by asking you to distinguish between what is syntactically valid versus common misconceptions. A frequent trap is assuming interfaces can be instantiated or contain private fields—they cannot, as fields are implicitly public static final, though private methods are allowed since Java 9. Remember the mnemonic “DIMPS”: Default methods, Instance methods (static), Multiple inheritance (via extends), Public fields (static final), and Static methods—all valid in modern interfaces.
1Z0-811 Object-Oriented Programming Practice Question
This 1Z0-811 practice question tests your understanding of object-oriented programming. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Which THREE statements are true about interfaces in Java? (Choose three.)
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
An interface can extend multiple interfaces
Options A, B, and D are correct. Interfaces can extend multiple interfaces using the extends keyword. Since Java 8, interfaces can contain static methods (with body) and default methods. Option C is wrong because interfaces cannot be instantiated directly. Option E is wrong because interface fields are implicitly public static final; private fields are not allowed (private methods are allowed since Java 9, but not fields).
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
An interface can be instantiated directly
Why it's wrong here
Interfaces are abstract types and cannot be instantiated.
✓
An interface can extend multiple interfaces
Why this is correct
Interfaces support multiple inheritance of type.
Related concept
Read the scenario before looking for a memorised answer.
✓
An interface can contain static methods
Why this is correct
Static methods are allowed in interfaces since Java 8.
Related concept
Read the scenario before looking for a memorised answer.
✓
An interface can contain default methods
Why this is correct
Default methods provide a default implementation in interfaces.
Related concept
Read the scenario before looking for a memorised answer.
✗
An interface can have private fields
Why it's wrong here
Interface fields are implicitly public static final; private fields are not supported.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
Use explanations to understand the rule behind the answer.
TExam Day Tips
→Underline the problem statement mentally.
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the 1Z0-811 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Identify which 1Z0-811 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Object-Oriented Programming — This question tests Object-Oriented Programming — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: An interface can extend multiple interfaces — Options A, B, and D are correct. Interfaces can extend multiple interfaces using the extends keyword. Since Java 8, interfaces can contain static methods (with body) and default methods. Option C is wrong because interfaces cannot be instantiated directly. Option E is wrong because interface fields are implicitly public static final; private fields are not allowed (private methods are allowed since Java 9, but not fields).
What should I do if I get this 1Z0-811 question wrong?
Identify which 1Z0-811 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This 1Z0-811 practice question is part of Courseiva's free Oracle certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 1Z0-811 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.