This 1Z0-811 practice question tests your understanding of arrays and methods. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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.
Exhibit
javac Test.java
Test.java:5: error: reference to print is ambiguous
print(null);
^
both method print(String[]) in Test and method print(String...) in Test match
Refer to the exhibit. Which overloaded methods cause this compilation error?
Exhibit
javac Test.java
Test.java:5: error: reference to print is ambiguous
print(null);
^
both method print(String[]) in Test and method print(String...) in Test match
A
public void print(String s) and public void print(String[] s)
Why wrong: This combination is valid because the first method takes a single String and the second takes a String array; they have different parameter types, so no compilation error.
B
public void print(String s) and public void print(String... s)
Why wrong: This combination is valid because a single String parameter and a varargs String parameter are different signatures; the compiler can distinguish between them, so no error.
C
public void print(String[] s) and public void print(String... s)
This combination causes a compilation error because a String array parameter and a String varargs parameter are considered the same after type erasure; the compiler sees them as duplicate methods.
D
public void print(Object... o) and public void print(String... s)
Why wrong: This combination is valid because the varargs are of different types (Object and String), so the method signatures are distinct; no compilation error.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
public void print(String[] s) and public void print(String... s)
Option C is correct because Java does not allow overloading methods that differ only by the use of a varargs parameter and an array parameter of the same type. Both `public void print(String[] s)` and `public void print(String... s)` have the same method signature after erasure — they both accept a `String[]` at the bytecode level — causing a compilation error due to ambiguity.
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.
✗
public void print(String s) and public void print(String[] s)
Why it's wrong here
This combination is valid because the first method takes a single String and the second takes a String array; they have different parameter types, so no compilation error.
✗
public void print(String s) and public void print(String... s)
Why it's wrong here
This combination is valid because a single String parameter and a varargs String parameter are different signatures; the compiler can distinguish between them, so no error.
✓
public void print(String[] s) and public void print(String... s)
Why this is correct
This combination causes a compilation error because a String array parameter and a String varargs parameter are considered the same after type erasure; the compiler sees them as duplicate methods.
Related concept
Read the scenario before looking for a memorised answer.
✗
public void print(Object... o) and public void print(String... s)
Why it's wrong here
This combination is valid because the varargs are of different types (Object and String), so the method signatures are distinct; no compilation error.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates mistakenly think varargs and arrays are distinct types for overloading, but Java treats them identically after compilation, so defining both `print(String[])` and `print(String...)` causes a duplicate method error.
Detailed technical explanation
How to think about this question
Under the hood, Java treats varargs (`String... s`) as syntactic sugar for an array (`String[] s`). When both a fixed-array method and a varargs method with the same element type are defined, the compiler sees two methods with identical erased signatures — `print(String[])` — leading to a duplicate method error. This is specified in JLS §8.4.2, which states that two methods cannot have the same name and parameter types after erasure. In real-world code, this often arises when refactoring from an array parameter to varargs without removing the original method.
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.
Arrays and Methods — This question tests Arrays and Methods — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: public void print(String[] s) and public void print(String... s) — Option C is correct because Java does not allow overloading methods that differ only by the use of a varargs parameter and an array parameter of the same type. Both `public void print(String[] s)` and `public void print(String... s)` have the same method signature after erasure — they both accept a `String[]` at the bytecode level — causing a compilation error due to ambiguity.
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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Question Discussion
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