5.13. Multiple Choice ExercisesΒΆ

Q1

What is the output of the code below?

int main() {
  int x = 0;
  int i = 1;
  while (i < 10) {
    x = i;
    i++;
  }
  cout << x;
}

Q2

What is the final value of i when the code is finished running?

int main() {
  int x = 0;
  int i = 1;
  while (i < 10) {
    x = i;
    i++;
  }
  cout << x;
}

Q3

How many times does the following while loop run?

int main() {
  int i = 6;
  while (i > 2) {
    i = i + 4;
    if (i > 8) {
      i = i - 5;
    }
  }
}

Q4

What is the output of the code below?

int main() {
  int n = 10;
  // cout << "Da ";
  cout << "na ";
  while (n != 3) {
    cout << "na ";
    n--;
  }
  cout << "Batman!";
}

Q5

What is the output of the code below?

int main() {
  int n = 10;
  cout << "Da ";
  cout << "na ";
  while (n != 3) {
    cout << "na ";
  }
  cout << "Batman!";
}

Q6

What is the output of the code below?

int main() {
  int x = 1;
  while (x < 6) {
    cout << x << '\t' << pow (x, 5) / pow (x, 3) << '\n';
    x++;
  }
}

Q7

Why are we allowed to use the variable x in both main and in the function definition of super_secret_function?

int super_secret_function (int n) {
  int x = 0;
  return (2 + (n * n) - 5 * n / 7) * x;
}

int main() {
  int x = 1;
  cout << "After using the super secret function, we get " << super_secret_function (x);
}

Q8

What is the output of the code below?

int loop_five (int n) {
  while (n % 5 != 0) {
    n = n + 3;
  }
  return n;
}

int main() {
  cout << loop_five (2);
  cout << loop_five (3);
  cout << loop_five (4);
}

Q9

The super evil villian re_pete wants to annoy the city by hacking into the city's helper robots and making them repeat everything they say 5 times. However, there's an error in his code and now the robots won't stop repeating! Can you find the error?

void repeat_bot (string input) {
  int n = 0;
  while (n < 5) {
    cout << input << ' ';
    n--;
  }
}

int main() {
  repeat_bot ("Hello, how may I help you?");
}

Q10

After making some changes to his code, re_pete tries again. This time, however, the robots don't repeat anything! Can you find the new error?

void repeat_bot (string input) {
  int n = 0;
  while (n > 5) {
    cout << input << ' ';
    n++;
  }
}

int main() {
  repeat_bot ("Hello, how may I help you?");
}