Difficulty: Medium
Correct Answer: No output is produced.
Explanation:
Introduction / Context:
This classic formatting puzzle tests how Java parses a do
-while
statement whose body is itself a while
statement. The key is understanding statement boundaries and which loop actually executes.
Given Data / Assumptions:
I
is initialized to 1.do
statement's body is a single while
statement: while (I < 1) System.out.print(...);
while (I > 1);
is the terminator of the do
loop.
Concept / Approach:
Evaluate the inner while (I < 1)
first: since I == 1
, it executes zero times and prints nothing. Then the outer do
-while
checks its condition (I > 1)
, which is false, so the entire construct ends with no output.
Step-by-Step Solution:
Inner while condition: I < 1
⇒ false
at entry ⇒ body never runs.The do
executes its single statement (the inner while) exactly once (doing nothing).Outer terminating condition: I > 1
⇒ false
; loop finishes.No print statements were executed ⇒ no output.
Verification / Alternative check:
Change I
to 0 and you will see "I is 0"
printed repeatedly until the outer condition stops it (it still won’t in this exact shape without changing I
).
Why Other Options Are Wrong:
They assume the print executes at least once or a compilation problem; the code is valid and the inner condition is false.
Common Pitfalls:
Misreading line breaks as scoping braces; Java does not add implicit blocks based on newlines or indentation.
Final Answer:
No output is produced.
Discussion & Comments