Exam 2 Practice Questions

Definitions

1. Match the term on the left to the definition on the right (Repetition).

2. Match the term on the left to the definition on the right (File I/O).

3. Match the term on the left to the definition on the right (Arrays).

4. Match the term on the left to the definition on the right (Functions).

Short Answer

5. What are the 3 different types of loops and how do they differ?

6. When is it best to use a while loop?

7. When is it best to use a do...while loop?

8. When is it best to use a for loop?

9. What is a loop control variable?

10. What happens if a loop control variable is not properly updated?

11. How do infinite loops present themselves in programs at runtime?

12. In general, what are the valid indices of a 1D array?

13. In 1 line of code, create a 1D array of strings and fill it with the 3 elements: luke skywalker, leia organa, and obi-wan kenobi.

14. What are the inbound indices of the 1D array created in the previous question?

15. What error can happen if an invalid index is accessed in an array?

16. In general, what does a segmentation fault mean?

17. What is a record of data?

18. How can 1000 records of data be stored in a program?

19. Explain how parallel arrays are created and maintained in a program.

20. How does a 2D array differ from a 1D array?

21. In 1 line create a 3x3 2D array of characters and fill it with the 9 elements: row 1: r, b, w, row 2: g, g, g, and row 3: y, r, r.

22. When accessing a 2D array element what 2 pieces of information need to be provided?

23. What is the difference between a function header and prototype?

24. What happens if a function prototype is forgotten?

25. What does a function prototype do?

26. What is a function signature?

27. Provide the signatures for the following functions:

    • int countOpenRides(string rides[], bool isOpen[])
    • void displayRides(string rides[], bool isOpen[])
    • string concatenate(string left, string right)
    • double area(double radius)
    • char continue()

28. Where does the code that will be executed when the function is called go?

29. What are parameters?

30. What is the difference between actual and formal parameters?

31. What is the difference between value and reference parameters?

32. What is the difference between a void and value-returning functions?

33. How are functions used?

34. What is the point of writing functions?

Error Code

35. In the following program fix all the errors (write the fixes directly on the code)

    
    #include <iostream>
    
    using namespace std;
    
    int main()
    
    {
    
      int end = 0, i = 0;
    
      // get valid number
      do
    
      {
    
        cout << “End: “;
    
        cin >> end;
    
        if (cin.fail() || i < 0)
    
        {
    
          cout << “Invalid number\n”;
    
          cin.clear();
    
          cin.ignore(256, ‘\n’);
    
        }
    
      } while (cin.fail() || i < 0);
    
      // output numbers between 0 and input number
      for (i <= end)
    
      {
    
        cout << i << endl;
    
        i++;
    
      }
    
      return 0;
    
    }

36. In the following program fix all the errors (write the fixes directly on the code)

    
    using namespace std;
    
    int main()
    
    {
    
      ifstream iFile;
    
      iFile >> variable;
    
      iFile.close();
    
      return 0;
    
    }

37. In the following program fix all the errors (write the fixes directly on the code)

    
    #include <iostream>
    
    using namespace std;
    
    int main()
    
    {
    
      int SIZE = 10;
    
      int arr[SIZE] = 0;
    
      // Print all array elements
      cout << arr << endl;
    
      return 0;
    
    }

38. In the following program fix all the errors (write the fixes directly on the code)

    
    #include <iostream>
    
    using namespace std;
    
    int main()
    
    {
    
      int ROWS = 5, COLUMNS = 3;
    
      int arr[ROWS][COLUMNS] = {};
    
      // Print all array elements
      for (int i = 0; i < ROWS; i++)
    
      {
    
        cout << arr[i] << endl;
    
      }
    
      return 0;
    
    }

39. In the following program fix all the errors (write the fixes directly on the code)

    
    #include <iostream>
    
    using namespace std;
    
    int main()
    
    {
    
      int i = multiplyBy3AndPrint();
    
      return 0;
    
    }
    
    void multiplyBy3AndPrint(int i);
    
    {
    
      int j = i * 3;
    
      cout << i << “ * 3 = “ << j << endl;
    
    }

Write a Function That...

40. Reads an integer from the user between a passed minimum and maximum value, then returns it.
    Prototype: int readInt(string prompt, int min, int max);

41. Calculates the volume of a sphere using the formula:

    $$v = \frac{4}{3} \pi r^3$$

    Prototype: double volume(double r);

42. Swaps 2 values in an array at the given indices.
    Prototype: void swap(int arr[], int left, int right);

43. Splits a string on a character. Return the part before the character from the function using the return keyword, and place the part after the character in the parameter updating it via reference.
    Prototype: string split(string &toSplit)

Practice Program

44. Write all preprocessor directives needed for the functions below.

45. Write a function:

    string getString(const string prompt)

    That prompts the user to enter a string using the passed prompt, verifies the string’s length is in range 0 < length < 30 (if an invalid length string is entered, output an error and retry until a valid lengthed string is input), and then returns the entered string once a valid lengthed string has been entered.

46. Write a function:

    string concatenate(const string str1, const string str2)

    Which will concatenate str1 to st2 and then return the new string.

47. Write a function:

    void printStringToFile(const string toPrint)

    Which outputs the passed toPrint parameter to a file "output.txt". This function will always output to the same file.

48. Using the functions written in the previous 3 questions, write a program that:

    a. Calls getString() passing it the prompt “\nEnter a string: ” and saving the result.

    b. Calls getString() passing it the prompt “\nEnter another string: ” and saving the result.

    c. Passes the 2 strings from (a) and (b) to concatenate() in that order and saves the result.

    d. Passes the string from (c) to printStringToFile().

    Example Program Interaction

    example $ ./a.out
    Enter a string:
    Error: invalid length
    
    Enter a string: This string is too long for this program to handle
    Error: invalid length
    
    Enter a string: A valid string
    My_prompt $ cat output.txt
    A valid string
    example $