CIS 150 C++ Spring 2017 Midterm exam #2 practice problem

Overview

Write a program to meet the listed requirements. Note: This includes more code than will be on the actual midterm #2.

Program requirements

1. Write documentation comments. They must include the name of the program, the date, the course number, and your name.
2. Use proper indentation throughout the program using four spaces per level of indent.
3. Use spaces and NO tabs for the indentation.
4. Write whatever include directives and using statements that your program needs.
5. Write a function prototype for a function named writeToFile that takes a string filename and an integer length. It returns a Boolean value.
6. Write a function prototype for a function named readFromFile that takes a string filename. It returns a Boolean value.
7. Write a function prototype for a function named fillArray that takes an integer array and an integer length. It returns nothing.
8. Write a function prototype for a function named displayArray that takes an integer array and an integer length. It returns nothing.
9. Write a function prototype for a function named sumArray that takes an integer array and an integer length. It returns an integer.
10. Write a function prototype for a function named writeArrayToFile that takes an ofstream reference, an integer array, and an integer length. It returns nothing.
11. In main
    • Initialize the random number generator.
    • Declare a string object named filename and initialize to "practice2.txt".
    • Declare a constant integer name SIZE and initialize to 12.
    • Declare an integer array of length SIZE.
    • Output the message: Basic file I/O test\n
    • Call writeToFile, sending it the filename and SIZE.
    • If writeToFile returned false, display an error message (Output file error).
    • If writeToFile returned true, then call readFromFile, sending it the filename.
    • If readFromFile returned false, then display an error message (Input file error).
    • Output the message: Array and file I/O test\n
    • Call fillArray, sending it the integer array and SIZE.
    • Call displayArray, sending it the integer array and SIZE.
    • Calling sumArray. sending it the integer array and SIZE.
    • Display the sum you got back from sumArray.
    • Declare an ofstream object and use filename to open it. Open it for appending.
    • If the output file failed to open, then display an error message.
    • If the output file did open, call writeArrayToFile, sending it the ofstream reference, the integer array, and SIZE. Then close the ofstream (file) object.
    • Call readFromFile, sending it the filename.
    • If readFromFile returned false, then display an error message (Input file error).
    • Return success (0).
12. Write a function named writeToFile
    • Parameters: string filename, integer length
    • Returns: true or false
    • Open file for output.
    • If there is an error, then return false.
    • If there is no error, then
      • Output length random numbers between 1 and 100 to file, with each one followed by a newline.
      • Close file.
      • Return true.
13. Write a function named readFromFile
    • Parameters: string filename
    • Returns: true or false
    • Open file for input.
    • If there is an error, then return false.
    • If there is no error, then
      • while you can read in an integer successfully, display that integer with a space after it.
      • Close the file.
      • Return true.
14. Write a function named fillArray
    • Parameters: an integer array and an integer length
    • Returns: nothing
    • Use a loop to set each element of the array to a random integer between 1 and 500.
15. Write a function named displayArray
    • Parameters: an integer array and an integer length
    • Returns: nothing
    • Use a loop to display each element of the array, with a space after each element.
    • Output a newline after all the elements are displayed.
16. Write a function named sumArray
    • Parameters: an integer array and an integer length
    • Returns: an integer
    • Use a loop to total up all the elements of the array.
    • Return the total.
17. Write a function named writeArrayToFile
    • Parameters: an ofstream reference, an integer array, and an integer length
    • Returns: nothing
    • Use a loop to output all the elements of the array to the ofstream (file), with a newline afetr each element.

Sample output run

    Basic file I/O test
    842 741 557 227 130 703 29 6 11 361 128 748
    Array and file I/O test
    495 24 382 129 154 490 95 114 231 261 392 37
    The sum of the array is 2804
    842 741 557 227 130 703 29 6 11 361 128 748 495 24 382 129 154 490 95 114 231 261 392 37