Java operators — which two expressions are equivalent for the integer value 16? Candidates: 1) 164 2) 16>>2 3) 16/2^2 4) 16>>>2 Assume 32-bit signed ints and Java operator precedence.
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A1 and 2
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B2 and 4
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C3 and 4
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D1 and 3
Answer
Correct Answer: 2 and 4
Explanation
Introduction / Context:This question reinforces the difference between arithmetic, shift, and bitwise XOR operators in Java, and highlights that ^ is XOR, not exponentiation. It asks which proposed expressions evaluate to the same result when applied to the integer 16.
Given Data / Assumptions:
- All operations are on ints.
>>is arithmetic right shift;>>>is logical right shift.^performs bitwise XOR, not power.
Concept / Approach:Right-shifting 16 by 2 gives 16 / 2^2 in the power sense, but since ^ is XOR, writing 16/2^2 is actually (16/2) ^ 2 by precedence, and since 2 ^ 2 == 0, the expression 16/0 is a constant-expression division by zero which is illegal at compile time. Meanwhile, 16 >> 2 and 16 >>> 2 both yield 4 for a nonnegative integer.
Step-by-Step Solution:
Compute 16 >> 2 → 4 (shift right by 2 bits).Compute 16 >>> 2 → 4 (logical right shift; same for nonnegative values).Expression 164 → 64 (not equal to 4).Expression 16/2^2 → invalid (compile-time error due to divide by zero).Verification / Alternative check:Evaluating on a REPL confirms both right-shift variants produce 4 for nonnegative inputs. For negative values, >> and >>> differ.
Why Other Options Are Wrong:
- Pairs involving 1 do not match 4.
- Pairs involving 3 use an invalid expression; equivalence cannot hold.
Common Pitfalls:Misreading ^ as exponent; in Java, there is no exponent operator—use Math.pow for powers.
Final Answer:2 and 4