CPA Testing, Debugging & Code Optimization 3

Question 1

What is 'mocking' in unit testing?

Accepted Answer

Replacing a dependency with a fake that records how it was called

Answer

A mock replaces a real dependency and also verifies that specific methods were called with expected arguments during the test.

Question 2

Which type of error is detected by the compiler before the program runs?

Accepted Answer

Syntax error

Answer

Syntax errors violate the grammatical rules of the programming language and are caught by the compiler or interpreter before execution begins.

Question 3

What does 'test-driven development' (TDD) require you to do first?

Accepted Answer

Write a failing test before writing code to pass it

Answer

TDD follows a red-green-refactor cycle: write a failing test first, then write the minimum code to make it pass, then refactor.

Question 4

Which data structure typically provides O(1) average-case lookup and is commonly used for caching optimizations?

Accepted Answer

Hash table

Answer

Hash tables map keys to values using a hash function, providing O(1) average-case lookup and making them ideal for caching and memoization.

Question 5

What is 'dead code' in software?

Accepted Answer

Code that is never executed during normal program operation

Answer

Dead code is source code that can never be reached or executed, often left over from refactoring, and should be removed to reduce maintenance burden.

(CPA) Certified Associate Programmer Practice Test