Question 1hardmultiple choice
Full question →- A
5.0
Why wrong: Incorrect.
- B
Compilation fails
Correct because narrowing conversion requires cast.
- C
5
Why wrong: Incorrect.
- D
Runtime error
Why wrong: Compilation error.
Question 100 of 509
Quick Answer
The answer is that the code fails to compile. This happens because Java enforces strict type safety and does not allow an implicit narrowing conversion from double to int, as double is a 64-bit floating-point type while int is a 32-bit integer type; allowing such an assignment without an explicit cast would risk silent loss of precision, such as truncating the fractional part. On the Oracle Java Foundations 1Z0-811 exam, this concept tests your understanding of primitive type conversions and the distinction between widening and narrowing assignments. A common trap is assuming that Java will automatically truncate the decimal value, but the compiler instead rejects the assignment outright. To remember this, think of the mnemonic "Narrow Needs a Cast" — whenever you move from a larger or more precise type to a smaller one, you must explicitly cast to satisfy the compiler.
1Z0-811 Primitives, Strings and Operators Practice Question
This 1Z0-811 practice question tests your understanding of primitives, strings and operators. 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.
Given: double d = 5.0; int i = d; What is the result?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Compilation fails
In Java, assigning a double to an int without an explicit cast causes a compilation error because double is a 64-bit floating-point type and int is a 32-bit integer type. Java does not allow implicit narrowing conversions due to potential loss of precision, so the code fails to compile.
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.
- ✗
5.0
Why it's wrong here
Incorrect.
- ✓
Compilation fails
Why this is correct
Correct because narrowing conversion requires cast.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
5
Why it's wrong here
Incorrect.
- ✗
Runtime error
Why it's wrong here
Compilation error.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Oracle often tests the distinction between implicit and explicit type conversion, and the trap here is that candidates assume Java will automatically truncate the decimal value (like in some other languages), forgetting that Java requires an explicit cast for narrowing conversions.
Detailed technical explanation
How to think about this question
Java's type system distinguishes between widening and narrowing primitive conversions. Widening (e.g., int to double) is automatic, but narrowing (e.g., double to int) requires an explicit cast like (int) d, which truncates the fractional part. This rule prevents silent data loss and is enforced by the compiler as per JLS §5.1.3. In real-world code, such a cast might be used when converting a floating-point calculation result to an integer index, but the programmer must explicitly acknowledge the truncation.
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.
TExam Day Tips
- 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 exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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Primitives, Strings and Operators — study guide chapter
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FAQ
Questions learners often ask
What does this 1Z0-811 question test?
Primitives, Strings and Operators — This question tests Primitives, Strings and Operators — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Compilation fails — In Java, assigning a double to an int without an explicit cast causes a compilation error because double is a 64-bit floating-point type and int is a 32-bit integer type. Java does not allow implicit narrowing conversions due to potential loss of precision, so the code fails to compile.
What should I do if I get this 1Z0-811 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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Last reviewed: Jun 30, 2026
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.
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