Multiple Choice Quiz

1. Which of these numeric types is represented using the fewest bytes in C++?

(A) long long

(B) int

(C) char

(D) float

(E) long

2. If I created an array of strings with "std::string word_list[5000]", what should I do when I'm done using word_list?

(A) for (auto x : word_list) delete x;

(B) delete [] word_list

(C) delete word_list

(D) Let the compiler take care of it when it falls out of scope

3. You want to execute code if either var1 is true or var2 is true, but not if they are both true. Given that both variables are type bool, three of the following techniques work; which one will NOT work?

(A) if ( var1 XOR var2) { ...code... }

(B) if ( var1 != var2) { ...code... }

(C) if ( (var1 || var2) && !(var1 && var2) ) { ...code... }

(D) if ( (var1 && !var2) || (var2 && !var1) ) { ...code... }

4. Which of the following is NOT a good reason a to define a member variable in the private section of a class definition?

(A) It will only be used in classes derived from this one

(B) It does not have a value that is meaningful outside of this class

(C) It is a pointer to memory that we don't want accessible outside of this class

(D) We may want to change the internals of the class in the future and don't want other classes depending on it

5. What does the following line of code do?
assert(x == 10);

(A) It checks to see if x is equal to 10; if not it sets x to 10 to ensure safe execution

(B) It checks to see if x is equal to 10; if not it prints an error and aborts the program

(C) It checks to see if x is equal to 10; if not it writes a warning and keeps going

(D) It prevents the program from compiling if it is possible for x to be a value other than 10

6. What is a difference between a native array (such as "int a[100]") and std::vector (such as "std::vector<int> v(100)")?

(A) A vector has member functions, but a native array does not

(B) A native array can be used in a range-based for loop, but a vector cannot

(C) A native array will always warn you at compile time if you index out of bounds, but a vector will not

(D) Vectors can be any number of dimensions, but arrays are limited to being one dimensional

7. Why should you use "include guards" (or #pragma once) in your header files?

(A) They ensure that files are included in the correct order

(B) They ensure that you do not duplicate identifiers if you include a file multiple times

(C) They guard against malicious code being injected into your program

(D) They make sure that your functions can only be called a single time

8. Which of the following is an illegal use of the keyword "auto"?

(A) const auto & my_err = std::cerr;

(B) auto my_str = std::string("Test.");

(C) auto my_var = std::string("abcd");

(D) auto i;

9. What will happen if you do not explicitly initialize an int variable?

(A) The variable will not have any memory allocated for it.

(B) The variable's scope will be adjust to where it is first used.

(C) Setting the variable later will be considered undefined behavior.

(D) The value of that variable will be undefined.

(E) The variable will be automatically initialized to zero by default.

10. What will the following code output?
std::vector<int> v{1,2,3,4};
std::cout << std::accumulate(v.begin()+1, v.end()-1, 0) << std::endl;

(A) 1

(B) 5

(C) 10

(D) 6

(E) 0