Multiple Choice Quiz

1. What is the difference between the keyword struct and the keyword class?

(A) A struct can only have public members, a class can also have private members

(B) A struct defaults to public members; a class defaults to private members

(C) Basic mathematical operations automatically run on struct, but not class

(D) Nothing: they can be used interchangeably

2. What is the value of var2 after the following code executes?
  int var1 = 5;
  var1 += 5;
  int var2 = 2 * var1++;

(A) 22

(B) 20

(C) 5

(D) 21

(E) 10

3. If you have a variable of type std::string called "age_str" which holds only digit characters and you want to convert it to a long called "age", which of these lines will work?

(A) long age = dynamic_cast<long>(age_str);

(B) long age = std::to_string(age_str);

(C) long age = std::stol(age_str);

(D) long age = static_cast<long>(age_str);

4. Assuming that x, y, and z are all defined, which of the following is true in c++:

(A) x => z will tell you if x is either equal to or greater-than z.

(B) y != z will tell you if y and z have different values.

(C) x === y will tell you if x and y are the exact same object.

(D) x < y < z will tell you if x, y, and z are in order from smallest to largest.

(E) More than one of the answers above is true.

5. Which of the following is a correct syntax for defining a lambda function in C++?

(A) auto f = (int x) { return x * x; };

(B) [](int x){ return x * x; };

(C) (int x) => x * x;

(D) lambda(int x) { return x * x; };

6. What is a difference between pointers and references in C++? +

(A) Pointers can be reassigned, while references cannot

(B) Pointers can be set at run time, while references are locked in at compile time

(C) Pointers can change the value of an object, while references cannot

(D) Pointers can point to multiple addresses at once, while references point to a single address

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

(A) The first index in a native array is 1, but the first index in a vector is 0

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

(C) Array are part of the base language and work anywhere, while vectors must be included from the standard library

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

8. What is the output from the following code fragment?
  char var1 = 'b';
  if (var1 == 'b') {
    int var2 = 10;
  }
  std::cout << var1 << var2 << std::endl;

(A) bb

(B) b

(C) b10

(D) 10b

(E) Nothing: it is illegal C++ code

9. What is the value of var2 after the following code executes?
  int var1 = 5;
  var1 += 5;
  int var2 = 2 * ++var1;

(A) 5

(B) 10

(C) 21

(D) 20

(E) 22

10. What will the following code print?
  for (int i = 0; i < 6; ++i) {
    if (i == 2) continue;
    if (i == 4) break;
    std::cout << i;
  }

(A) 01

(B) 0123

(C) 013

(D) 0134

(E) 2