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Please read the directions and wrote the program in C++   File Access and Pseudocode   Critical Review   When a program needs to save data for later use, it writes the data to a file

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Please read the directions and wrote the program in C++

 

File Access and Pseudocode

 

Critical Review

 

When a program needs to save data for later use, it writes the data to a file.  The data can be read from the file at a later time.

 

Three things must happen in order to work with a file.  1) Open a file.  2) Process the file.  3)  Close the file.

 

An internal file must be created for an output file or input file, such as:

 

     Declare OutputFile outFile  // to write out

     Declare InputFile inFile    // to read in

 

A data file must also be created to store the output, such as: 

    

     Open outFile "thedata.txt"

 

New operations include the following:

    

     Open InternalName "FileName"

     Write InternalName String or Data

     Read InternalName Data

     Close InternalName

 

Loops are used to process the data in a file.  For example:

 

     For counter = 1 to 5

        Display "Enter a number:"

        Input number

        Write outFile number

     End For

 

When reading information from a file and it is unknown how many items there are, use the eof function.  It is similar to a sentinel loop.  For example:

     Read inFile number  

     While NOT eof(inFile)

        Display number

        Read inFile number

          End While

 

 

 

This lab examines how to work with a file by writing pseudocode.  Read the following programming problem prior to completing the lab.  The following program from Lab 8 will be used, with some modifications.  

 

The American Red Cross wants you to write a program that will calculate the average pints of blood donated during a blood drive.  The program should take in the number of pints donated during the drive, up to twenty-four-hour drive period, from an input file, bloodDrive.txt.  The average pints, highest pints, and lowest pints donated during that period should be calculated and written to a file called bloodResults.txt.  We will only run the program once so a yes/no loop is not needed. 

 

Step 1:  Note that the getHigh, getLow, and getAverage functions do not change.  We need to modify modules getPints and displayInfo to meet the new requirements.  Complete the pseudocode below for the two modules according to instructions:

 

In the getPints Module (notice there is a new pass-by-reference parameter count)

1. Declare an input file with the name bloodInFile.
2. Open the internal file (bloodInFile) and a text file named bloodDrive.txt.
3. If cannot open file then display an error message
4. Set count = 0
5. Input one value from the file
6. While not end-of-file, store value in the array[count], add 1 to count, and input another value
7. Close the file.

 

Module getPints(Real pints[], Integer Ref count)

 

End Module

In the displayInfo Module

1. Declare an output file with the name bloodOutFile.
2. Open the internal file (bloodOutFile) and a text file named bloodResults.txt.
3. Write the string "Report generated by [YourName] " to the file.
4. Write the string "Blood drive period: " to the file.
5. Write the value of hours to the file.
6. Write the string "Average Pints: " to the file.
7. Write the value of averagePints to the file.
8. Do the same thing for highest pints and lowest pints
9. Close the bloodOutFile.

 

Module displayInfo(Integer hours, Real averagePints,

Real highPints, Real lowPints,)

 

 

 

 End Module

 

Pseudocode for the main module (MAX_HOURS is a global named constant)

Module main()

     //Declare local variables

     Declare Real pints[MAX_HOURS]

     Declare Integer hours

     Declare Real avePints, highPints, lowPints

          

     Call getPints(pints, hours)

     Display "hours: ", hours

Display "first value: ", hours[0]
Display "last value:  ", hours[hours - 1]

     Set avePints = getAverage(pints, hours)

     Set highPints = getHigh(pints, hours)

     Set lowPints = getLow(pints, hours)

     Call displayInfo(hours, avePints, highPints, lowPints)

End Module

 

File Access and C++ Code

The goal of this lab is to convert the blood drive program from above to C++ code.  Create a text file name bloodDrive.txt in the project folder with the following values (or you can also get it from Canvas).  Make sure to put one blank line after the last value.

43

25

64

35

19

37

46

 

Run your program and check against the following output file, bloodResults.txt.  If there are errors, go back through the steps to troubleshoot.   You should confirm that the program displays 7, 43, and 46 to the screen for hours, first value, and last value.

 

Report generated by [YourName]

Blood drive period:  7

Average pints:      38.4

Highest pints:      64.0

Lowest pints:       19.0

 

You might want to try another test case with fewer or more than 7 values to make sure your program can handle it.  Don't forget to include <fstream> for file input and output.  You would need to include <iomanip> and set the precision for the output file (not cout) to get one digit after the decimal point.  When your code is complete and runs properly, copy/paste both the source code and the output file (bloodResults.txt) for the test case above. 

 

Describe your experience and lessons learned with this lab.