CPA Testing, Debugging & Code Optimization 2 ā Questions and Answers
Question 1: Which testing approach tests the internal logic and structure of the code rather than just its external behavior?
- Black-box testing
- White-box testing (Correct answer)
- Regression testing
- Acceptance testing
Correct answer: White-box testing
White-box testing examines the internal code structure, branches, and paths, unlike black-box testing which only evaluates inputs and outputs.
Question 2: What is a 'breakpoint' in the context of debugging?
- A line where the program crashes
- A marker that pauses execution so the developer can inspect state (Correct answer)
- A syntax error in the code
- A test that intentionally fails
Correct answer: A marker that pauses execution so the developer can inspect state
A breakpoint is a deliberate stopping point set by the developer in a debugger to pause program execution and examine variables and flow.
Question 3: Which metric measures the percentage of source code lines executed during testing?
- Cyclomatic complexity
- Code coverage (Correct answer)
- Defect density
- Test velocity
Correct answer: Code coverage
Code coverage (specifically line coverage) reports what percentage of code lines were executed by the test suite.
Question 4: What is the purpose of a stub in unit testing?
- To generate random test data
- To replace a real dependency with a minimal controlled implementation (Correct answer)
- To measure execution time of a function
- To document test cases
Correct answer: To replace a real dependency with a minimal controlled implementation
A stub replaces a real dependency (like a database or API) with a simple controlled version so the unit under test can run in isolation.
Question 5: Which optimization technique moves a loop-invariant computation outside of the loop?
- Loop unrolling
- Loop hoisting (code motion) (Correct answer)
- Memoization
- Dead code elimination
Correct answer: Loop hoisting (code motion)
Loop hoisting (also called loop-invariant code motion) moves calculations whose result does not change across iterations outside the loop to avoid redundant work.
Question 6: What does 'regression testing' primarily verify?
- New features work correctly
- Previously working functionality has not been broken by recent changes (Correct answer)
- Code meets performance benchmarks
- Security vulnerabilities are absent
Correct answer: Previously working functionality has not been broken by recent changes
Regression testing re-runs existing tests after code changes to confirm that previously working behavior has not been inadvertently broken.
Question 7: In big-O notation, which complexity grows most slowly as input size increases?
- O(n)
- O(log n) (Correct answer)
- O(n log n)
- O(nĀ²)
Correct answer: O(log n)
O(log n) grows much more slowly than linear O(n) time, making logarithmic algorithms highly efficient for large inputs.
CPA Testing, Debugging & Code Optimization 2
Which testing approach tests the internal logic and structure of the code rather than just its external behavior?