Question

In this assessment, you will debug and fix a given Java console application that uses 2 dimensional arrays but the application does not compile nor execute. You can use either the Toolwire environment or your local Java development environment to complete this assignment.The application has four bugs. Your assignment is to find these bugs and fix them so that the application meets its stated requirements.The requirements of this application are as follows: The application is register students for courses in a term of study.

The assumptions used by the application are:

Student enters only integers to select courses for registration from a menu. No data type validation of the user menu selection is checked or required.

The program terminates only when the student closes it

The program must follow these registration business rules:

No registration of other courses not displayed by the program

  No registration more than once for the same course

  No registration for more than 9 credit hours (e.g. no more than 3 courses)

Use these course codes, in this order, to test your application:

IT4079

IT1006

IT2230

Please comment throughout code what you used different and explain why you used it or in a paragraph below the code.

package u8a1_2dconsoleregisterforcourse;

import java.util.Scanner;

public class U8A1_2DConsoleRegisterForCourse {

/**
* @param args the command line arguments
*/
public static void main(String[] args) {
// TODO code application logic here
  
System.out.println("Teacher's Copy");
  
Scanner input = new Scanner(System.in);
  
// courses 2d array hold course code and their credit hours
String[][] courses = {
{"IT1006", "IT4782", "IT4789", "IT4079", "IT2230", "IT3345", "IT2249"},
{"6", "3", "3", "6", "3", "3", "6"}
};
  
// validChoices 2d array holds valid number choices (as strings) selected by user
// and their corresponding courses
//e.g String[][] choices = { {"5", "IT2230"}, {"1", "IT1006"}, {"6", "IT3345"} };
String[][] validChoices = {
{"", ""},
{"", ""},
{"", ""}
};
  
int choice;
int totalCredit = 0;
String yesOrNo = "";

  
do {

choice = getChoice(courses, input);
  
switch (ValidateChoice(choice, validChoices, totalCredit, courses)) {
case -1:
System.out.println("**Invalid** - Your selection of " +
choice + " is not a recognized course.");
break;
case -2:
System.out.println("**Invalid** - You have already registerd for this " +
courses[0][choice-1] + " course.");
break;
case -3:
System.out.println("**Invalid** - You can not register for more than 9 credit hours.");
break;
case 0:
System.out.println("Registration Confirmed for course " +
courses[0][choice-1] );
totalCredit += Integer.parseInt(courses[1][choice-1]);
if (validChoices[0][0].equals("")) {
validChoices[0][0] = Integer.toString(choice);
validChoices[0] = courses[0][choice-1];
} else if (validChoices[1][0].equals("")) {
validChoices[1][0] = Integer.toString(choice);
validChoices[1][1] = courses[0][choice-1];
} else if (validChoices[2][0].equals("")) {
validChoices[2][0] = Integer.toString(choice);
validChoices[2][1] = courses[0][choice-1];
}
break;
}

WriteCurrentRegistration(validChoices, totalCredit);
  
System.out.print("\nDo you want to try again? (Y|N)? : ");
  
yesOrNo = input.next().toUpperCase();
  
} while (yesOrNo.equals("Y"));

System.out.println("Thank you for registering with us");
  
}

//This method prints out the selection menu to the user in the form of
//[selection number]Course Code (Course Credit Hours)
//from the courses array one per line
//and then prompts the use to make a number selection
public static int getChoice(String[] courses, Scanner input) {
System.out.println("Please type the number inside the [] to register for a course");
System.out.println("The number inside the () is the credit hours for the course");
for(int i = 0; i < courses[0].length; i++ )
System.out.println("[" + (i+1) + "]" + courses[0][i] + "(" + courses[1][i] + ")");
System.out.print("Enter your choice : ");
return (input.nextInt());
}

  

//This method validates the user menu selection
//against the given registration business rules
//it returns the following code based on the validation result
// -1 = invalid, unrecognized menu selection
// -2 = invalid, alredy registered for the course
// -3 = invalid, No more than 9 credit hours allowed
// 0 = menu selection is valid
public static int ValidateChoice(int choice, String[][] validChoices, int totalCredit, String[][] courses) {
String choiceAsString = Integer.toString(choice);
if (choice < 1 || choice > 7)
return -1;
else if (choiceAsString.equals(validChoices[0][0])
|| choiceAsString.equals(validChoices[])
|| choiceAsString.equals(validChoices[2][0]))
return -2;
else if ( totalCredit + Integer.parseInt(courses[1][choice-1]) > 9)
return -3;
return 0;
}
  
  
//This method prints the current list of registered courses thus far
//from the courses array separated by , and enclosed inside { }
//It also prints the total credit registered for thus far
public static void WriteCurrentRegistration(String[][] validChoices, int totalCredit) {

if (validChoices[0][0].equals(""))
System.out.println("Current course registration: { none } " );   
else if (validChoices[1][0].equals(""))
System.out.println("Current course registration: { " + validChoices[0][i] + " }" );
else if (validChoices[2][0].equals(""))
System.out.println("Current course registration: { " + validChoices[0][1] +
", " + validChoices[1][1] + " }");
else
System.out.println("Current course registration: { " + validChoices[0][1] +
", " + validChoices[1][1] + ", " + validChoices[2][1] + " }");
System.out.println("Current registration total credit = " + totalCredit);
}
  
}

Answer 1

solution

//corrected code

import java.util.Scanner;

public class U8A1_2DConsoleRegisterForCourse {

/**

* @param args the command line arguments

*/

public static void main(String[] args) {

// TODO code application logic here

System.out.println("Teacher's Copy");

Scanner input = new Scanner(System.in);

// courses 2d array hold course code and their credit hours

String[][] courses = {

{"IT1006", "IT4782", "IT4789", "IT4079", "IT2230", "IT3345", "IT2249"},

{"6", "3", "3", "6", "3", "3", "6"}

};

// validChoices 2d array holds valid number choices (as strings) selected by user

// and their corresponding courses

//e.g String[][] choices = { {"5", "IT2230"}, {"1", "IT1006"}, {"6", "IT3345"} };

String[][] validChoices = {

{"", ""},

{"", ""},

{"", ""}

};

int choice;

int totalCredit = 0;

String yesOrNo = "";

do {

choice = getChoice(courses, input);

switch (ValidateChoice(choice, validChoices, totalCredit, courses)) {

case -1:

System.out.println("**Invalid** - Your selection of " +

choice + " is not a recognized course.");

break;

case -2:

System.out.println("**Invalid** - You have already registerd for this " +

courses[0][choice-1] + " course.");

break;

case -3:

System.out.println("**Invalid** - You can not register for more than 9 credit hours.");

break;

case 0:

System.out.println("Registration Confirmed for course " +

courses[0][choice-1] );

totalCredit += Integer.parseInt(courses[1][choice-1]);

if (validChoices[0][0].equals("")) {

validChoices[0][0] = Integer.toString(choice);

validChoices[0][1] = courses[0][choice-1];

} else if (validChoices[1][0].equals("")) {

validChoices[1][0] = Integer.toString(choice);

validChoices[1][1] = courses[0][choice-1];

} else if (validChoices[2][0].equals("")) {

validChoices[2][0] = Integer.toString(choice);

validChoices[2][1] = courses[0][choice-1];

}

break;

}

WriteCurrentRegistration(validChoices, totalCredit);

System.out.print("\nDo you want to try again? (Y|N)? : ");

yesOrNo = input.next().toUpperCase();

} while (yesOrNo.equals("Y"));

System.out.println("Thank you for registering with us");

}

//This method prints out the selection menu to the user in the form of

//[selection number]Course Code (Course Credit Hours)

//from the courses array one per line

//and then prompts the use to make a number selection

public static int getChoice(String[][] courses, Scanner input)

{

System.out.println("Please type the number inside the [] to register for a course");

System.out.println("The number inside the () is the credit hours for the course");

for(int i = 0; i < courses[0].length; i++ )

System.out.println("[" + (i+1) + "]" + courses[0][i] + "(" + courses[1][i] + ")");

System.out.print("Enter your choice : ");

return (input.nextInt());

}

//This method validates the user menu selection

//against the given registration business rules

//it returns the following code based on the validation result

// -1 = invalid, unrecognized menu selection

// -2 = invalid, alredy registered for the course

// -3 = invalid, No more than 9 credit hours allowed

// 0 = menu selection is valid

public static int ValidateChoice(int choice, String[][] validChoices, int totalCredit, String[][] courses) {

String choiceAsString = Integer.toString(choice);

if (choice < 1 || choice > 7)

return -1;

else if (choiceAsString.equals(validChoices[0][0])

|| choiceAsString.equals(validChoices[1][0]) //error

|| choiceAsString.equals(validChoices[2][0]))

return -2;

else if ( totalCredit + Integer.parseInt(courses[1][choice-1]) > 9)

return -3;

return 0;

}

//This method prints the current list of registered courses thus far

//from the courses array separated by , and enclosed inside { }

//It also prints the total credit registered for thus far

public static void WriteCurrentRegistration(String[][] validChoices, int totalCredit) {

if (validChoices[0][0].equals(""))

System.out.println("Current course registration: { none } " );  

else if (validChoices[1][0].equals(""))

System.out.println("Current course registration: { " + validChoices[0][1] + " }" );

else if (validChoices[2][0].equals(""))

System.out.println("Current course registration: { " + validChoices[0][1] +

", " + validChoices[1][1] + " }");

else

System.out.println("Current course registration: { " + validChoices[0][1] +

", " + validChoices[1][1] + ", " + validChoices[2][1] + " }");

System.out.println("Current registration total credit = " + totalCredit);

}

}

//output