Free Test Function objects functors – C++ Lan...

Q1: What is a functor in C++ STL?

A. An object that can be called like a function B. A function pointer C. A regular function D. A container

Q2: Which operator is overloaded in a functor?

A. operator() B. operator+ C. operator= D. operator*

Q3: What advantage do functors have over function pointers?

A. Can hold state B. Faster execution C. Use less memory D. Cannot be copied

Q4: Which STL algorithm commonly uses functors?

A. sort B. for_each C. copy D. find

Q5: What header defines standard function objects like std::plus?

A. <functional> B. <algorithm> C. <iostream> D. <iterator>

Q6: Which of the following is a standard unary function object?

A. std::negate B. std::plus C. std::multiplies D. std::modulus

Q7: Which of the following is a standard binary function object?

A. std::negate B. std::logical_not C. std::plus D. std::bind1st

Q8: Can functors be passed as template arguments?

A. Yes B. No C. Only function pointers D. Only lambdas

Q9: Which of these is NOT a feature of functors?

A. Can maintain state B. Can be inlined by compiler C. Can be passed to algorithms D. Cannot be assigned

Q10: What does std::bind1st do?

A. Binds first argument of binary function B. Binds second argument of unary function C. Creates a functor from a member function D. Creates a function pointer

Q11: What is the main purpose of std::function?

A. To store and invoke any callable target B. To replace function pointers C. To create function templates D. To bind arguments

Q12: Which of the following can be used to create functors easily?

A. Lambda expressions B. Function pointers C. Class templates D. Type aliases

Q13: Which STL header is needed for std::function?

A. <functional> B. <utility> C. <algorithm> D. <iterator>

Q14: Can functors be used with std::sort?

A. Yes B. No C. Only function pointers D. Only lambdas

Q15: Which keyword is used to make operator() const in functors?

A. const B. mutable C. virtual D. explicit

Q16: Are functors always stateful?

A. No, they can be stateless B. Yes, always C. Only if template is used D. Only if inherited

Q17: What is the benefit of inlining functors?

A. Improved performance B. Less memory usage C. Better type safety D. Reduced compilation time

Q18: Which of these can be used to create custom comparison logic for sorting?

A. Functors B. Function pointers C. Lambdas D. All of the above

Q19: Can functors be templates?

A. Yes, template functors are common B. No, functors cannot be templates C. Only class templates can be functors D. Only function templates can be functors

Quiz for Function objects functors