CMPS 221 - Homework 6

Homework 6 - Structures

Due: Monday November 15, 2010 at 5:00pm

The purpose of this assignment is to create a small student gradebook using an array of structures. Each structure will be a single student record for the class. Name your source code hw6.cpp.

The structure should be called StudentRecord. It will have the following member variables:

A C-style string (character array) for the student's full name (you can choose the maximum name length, but make it reasonable such as 30 characters).
A C-style string for the student ID number (9 characters + 1 for the null character).
An integer array that stores 4 exam scores.
A double for the overall class grade. You will calculate this value based on the user input for exam scores. The overall grade will be the average of the exam scores.

You MUST enforce the following data constraints when reading input from the user. Use an input validation loop to reject any invalid input and ask the user for new data:

There must be at least one character to the name (strlen() will return the number of characters in a C-style string).
There must be exactly 9 digits in the student ID. You must check that each character is a digit (the isdigit() function will be useful here).
Each exam score must be in the range of 0 to 100.

In main(), you will create an array of StudentRecords and use a menu to manipulate this array. As with Homework 5, each menu item will call a function, passing the array to the function. The ONLY global variable allowed will be the maximum capacity of the array. ALL other variables MUST be local to their functions or the main() function.

Use the following menu for the program:

  Welcome to the StudentRecord Gradebook
  ======================================
  1.  Enter student data for the class
  2.  Print all student records
  3.  Print a single student record

  0.  Exit
  ======================================
  Enter selection:

You will be using a variety of functions to implement these options. Option 1 will call an overall getAllStudents() function. Option 2 will check if student data has been entered. If there are students, it will call a printAllStudents() function. If there are no students, it will remind the user to select Option 1 first. Option 3 will also check if student data has been entered and remind the user to select Option 1 first if there are no students. If there are students, Option 3 will call the printSelectedStudent() function.

The required functions are as follows:

getStudent - This is a void function. It will take a SINGLE by-reference StudentRecord object as an argument. This function will prompt the user for the student name, student ID and exam scores. It will read in the name using getline(), the ID using either getline() or the extraction operator and the exam scores using the extraction operator. (NOTE: Since you will be using both getline() and the extraction operator, be SURE to call cin.ignore() BEFORE reading the student's name to throw away the enter key character on the input stream). The function MUST check each data item entered by the user following the data constraint rules listed above. Once all the data has been correctly entered by the user, the function will calculate and set the overall course grade.
getAllStudents - This is a void function. It will take two arguments: an array of StudentRecord objects and a by-reference integer for the size. It will prompt the user for the number of students to enter and verify that the number of students is between 0 and the maximum capacity of the array. It will then loop for each student record, calling the getStudent() function on each StudentRecord object.
printStudent - This is a void function. It will take a SINGLE, constant by-reference StudentRecord object as an argument. This function will print the current student information, using setw() or printf to set column widths on each field (e.g. use a column width of 10 for the student ID). The overall course grade should be printed with 2 decimal places of precision. A student record should resemble the following when printed:
```
John Doe             000561234   75   85   80   92      83.00%
```
printAllStudents - This is a void function. It will take two arguments: a constant array of StudentRecord objects and a by-value integer for size. For each record in the array, it will print the index number of that record (e.g. the current value of i) and then call the printStudent() function on that StudentRecord object. Note that you should also set a column width using either setw() or printf() when printing the index number. The output of this function should resemble the following:
```
Index   Name                ID          Exam Grades            Overall Grade
0       John Doe            000561234   75   85   80   92      83.00%
1       Jane Smith          999123456   80   86   89   90      86.25%
2       Bob Smith           999654321   85   86   85   91      86.75%
```
printSelectedStudent - This is a void function. It will take two arguments: a constant array of StudentRecord objects and a by-value integer for size. This function will ask the user for the index number of the student they wish to print. The program MUST verify that the index number is between 0 and size-1. If the index number is valid, call the printStudent() function for that index. Otherwise, print an error message to the user and exit the function (returning to the menu where they can attempt to print a selected student again by selecting Option 3 again). Do NOT have an input validation loop for the index number, just have an if-else statement.

Email your completed source code to me.