Working with Arrays and Collections →easyMultiple ChoiceObjective-mapped

1Z0-829 Working with Arrays and Collections Practice Question

Which of the following creates an immutable map with two entries?

⚠ Common exam trap

Watch out — candidates often confuse creating a mutable copy of an immutable map (option A) with the immutable map itself, or they overlook that `Map.of()` directly produces an immutable map without needing a wrapper.

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

✓

Map.of("a",1,"b",2)

`Map.of()` returns an immutable map containing exactly the key-value pairs provided as arguments. This factory method was introduced in Java 9 and creates a fixed-size, unmodifiable map with the two entries "a"→1 and "b"→2.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✗
new HashMap<>(Map.of("a",1,"b",2))
Why it's wrong here
Incorrect: this creates a mutable copy of the immutable map.
✓
Map.of("a",1,"b",2)
Why this is correct
Correct: returns an immutable map with two entries.
✗
Collections.emptyMap()
Why it's wrong here
Incorrect: this returns an empty immutable map.
✗
None of the above
Why it's wrong here
Incorrect: Map.of works.
✗
new HashMap<>()
Why it's wrong here
Incorrect: this creates an empty mutable map.

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1Z0-829 Working with Arrays and Collections Practice Question

Why each option matters

Option-by-option breakdown

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