Syntax Fundamentals & Data Structures Flashcards
7 cards from real CPP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Syntax Fundamentals & Data Structures flashcards as text
What does 'std::move' do to an object?
Answer: Casts the object to an rvalue reference, enabling move semantics
std::move is a cast to rvalue reference; it signals that the object's resources can be transferred rather than copied.
Which STL data structure provides LIFO (Last-In, First-Out) behavior?
Answer: std::stack
std::stack implements LIFO semantics; elements are pushed and popped from the same end (top).
What is the result of this expression in C++? ```cpp std::cout << (true + true + false); ```
Answer: 2
In arithmetic context, true converts to 1 and false to 0, so 1+1+0 = 2.
What is a 'dangling pointer' in C++?
Answer: A pointer that points to memory that has been freed or gone out of scope
A dangling pointer points to memory that is no longer valid, such as after delete or when a local variable's scope ends.
Which keyword is used to prevent a derived class from overriding a virtual function in C++11 and later?
Answer: final
The 'final' specifier prevents further overriding of a virtual function in derived classes.
What is the time complexity of inserting an element at the front of a std::deque?
Answer: O(1)
std::deque supports O(1) amortized insertion at both front and back, unlike std::vector which is O(n) at the front.
What does the 'explicit' keyword do when applied to a constructor?
Answer: Prevents the constructor from being used for implicit type conversions
The explicit keyword prevents the compiler from using that constructor for implicit single-argument conversions.