Newbie with questions

[buzzdsm]

I'm 2 weeks in a basic Java class and I'm having all kinds of problems with an assignment. Here is the assignment(in red). Can someone help a newbie out?

Use this UML diagram to create the class

InternetCharges

-pkg:char
-hours:double
+InternetCharges(p:char, h:double)
+setPkg(p:char):void
+setHours(h:double):void
+getPkg():char
+getHours():double
+getChanges():double


XY_Prog4_11 Modify the data in the program so it matches these Sample Runs:

Welcome to Satellite Internet Connect
Packages:
A: 512Kbps $49.95, 40 hrs/month, $2/hr over 40 hrs
B: 1.0 Mbps $69.95 80 hrs/month, $1/hr over 80 hrs
C: 1.5Mbps unlimited hours
Enter the customer's package A, B, or C: A
Enter the number of hours used: 45
The charges are $59.95


Welcome to Satellite Internet Connect
Packages:
A: 512Kbps $49.95, 40 hrs/month, $2/hr over 40 hrs
B: 1.0 Mbps $69.95 80 hrs/month, $1/hr over 80 hrs
C: 1.5Mbps unlimited hours
Enter the customer's package A, B, or C:

Here is what I have so far

public class InternetCharges
{
	private char pkg;   			//Customers package
	private double hours;		//Number of hours used
	
	/**
	 *The constructor uses two parameters to accept
	 *arguments: p and h. The value in p is assigned to
	 *the pkg field and the value in h is assigned to
	 *the hours field. The InternetCharges method is called
	 */
	 
	 public InternetCharges(char p, double h)
	 {
	 	pkg=p;
		hours=h;
	 }

   /**
	 *The getPkg method returns the pkg field
	 */
	 
	 public char getPkg()
	 {
	 	return pkg;
	 }
	 
	/**
	 *The getHours method returns the hours field
	 */
	 
	 public double getHours()
	 {
	 	return hours;
	 }
	 
	/**
	 *The getCharges method returns the charges field.
	 */
	 
	 public double getCharges()
	 {
	 		
	 	if (pkg = A)
		baseCharge = 49.95;
		addedCharge = (hours - 40)* 2.00;  //2.00 per hour
		totalCharge = baseCharge + addedCharge;
		else if (pkg = B)
		baseCharge = 69.95;
		addedCharge = (hours - 80) * 1.00;  //1.00 per hour
		totalCharge = baseCharge + addedCharge;
		else if (pkg = C)
		baseCharge = 79.95;
		totalCharge = baseCharge;
	
		return charges;

	 }
	 }

import java.util.Scanner;   //Scanner class

/**
 *This program demo's internet charges
 */
 
 public class IntChargesRun
 {
 	public static void main(String[] args)
	{
	   String input;
		char pkg;        //Package A, B, or C
		double hours;    //Number of hours used
	
		
		Scanner keyboard = new Scanner(System.in); //Scanner for keyboard input
		
		
		
		//Display instructions
		System.out.println("Welcome to Satellite Internet Connect Packages:" + '\n' +
								 "A: 512Kbps $49.95, 40 hrs/month, $2/hr over 40 hrs" + '\n' +
								 "B: 1.0Mbps $69.95, 80 hrs/month, $1/hr over 80 hrs" + '\n' +
								 "C: 1.5Mbps unlimited hours" + '\n');
								 
		//Customers package type
		System.out.println("Enter the customer's package A, B, or C: ");
		pkg = input.charAt(0);                    //Gets the first character
		
		//Number of hours used
		System.out.println("Enter the number of hours used: ");	
		hours = keyboard.nextDouble();            //gets hours
		
		InternetCharges ichgs = new InternetCharges(pkg, hours);
		double c = ichgs.getCharges();
		System.out.println (c);	
		
			
		}
	}

[Zosden]

Whats the problem. Can you give us clues to what kind of trouble your having.

[buzzdsm]

----jGRASP exec: javac -g C:\Program Files\Java\jdk1.5.0_15\bin\InternetCharges.java

InternetCharges.java:55: 'else' without 'if'
else if (pkg = B)
^
InternetCharges.java:59: 'else' without 'if'
else if (pkg = C)
^
2 errors

----jGRASP wedge2: exit code for process is 1.
----jGRASP: operation complete.

[buzzdsm]

----jGRASP exec: javac -g C:\Program Files\Java\jdk1.5.0_15\bin\IntChargesRun.java

InternetCharges.java:55: 'else' without 'if'
else if (pkg = B)
^
InternetCharges.java:59: 'else' without 'if'
else if (pkg = C)
^
InternetCharges.java:51: cannot find symbol
symbol : variable A
location: class InternetCharges
if (pkg = A)
^
InternetCharges.java:51: incompatible types
found : char
required: boolean
if (pkg = A)
^
InternetCharges.java:52: cannot find symbol
symbol : variable baseCharge
location: class InternetCharges
baseCharge = 49.95;
^
InternetCharges.java:53: cannot find symbol
symbol : variable addedCharge
location: class InternetCharges
addedCharge = (hours - 40)* 2.00; //2.00 per hour
^
InternetCharges.java:54: cannot find symbol
symbol : variable totalCharge
location: class InternetCharges
totalCharge = baseCharge + addedCharge;
^
InternetCharges.java:54: cannot find symbol
symbol : variable baseCharge
location: class InternetCharges
totalCharge = baseCharge + addedCharge;
^
InternetCharges.java:54: cannot find symbol
symbol : variable addedCharge
location: class InternetCharges
totalCharge = baseCharge + addedCharge;
^
InternetCharges.java:57: cannot find symbol
symbol : variable addedCharge
location: class InternetCharges
addedCharge = (hours - 80) * 1.00; //1.00 per hour
^
InternetCharges.java:58: cannot find symbol
symbol : variable totalCharge
location: class InternetCharges
totalCharge = baseCharge + addedCharge;
^
InternetCharges.java:58: cannot find symbol
symbol : variable baseCharge
location: class InternetCharges
totalCharge = baseCharge + addedCharge;
^
InternetCharges.java:58: cannot find symbol
symbol : variable addedCharge
location: class InternetCharges
totalCharge = baseCharge + addedCharge;
^
InternetCharges.java:61: cannot find symbol
symbol : variable totalCharge
location: class InternetCharges
totalCharge = baseCharge;
^
InternetCharges.java:61: cannot find symbol
symbol : variable baseCharge
location: class InternetCharges
totalCharge = baseCharge;
^
InternetCharges.java:63: cannot find symbol
symbol : variable charges
location: class InternetCharges
return charges;
^
16 errors

----jGRASP wedge2: exit code for process is 1.
----jGRASP: operation complete.

[Zosden]

public double getCharges()
	 {
	 		
	 	if (pkg = A)
                {
		     baseCharge = 49.95;
		     addedCharge = (hours - 40)* 2.00;  //2.00 per hour
		     totalCharge = baseCharge + addedCharge;
                }
		else if (pkg = B)
                {
		      baseCharge = 69.95;
		      addedCharge = (hours - 80) * 1.00;  //1.00 per hour
		      totalCharge = baseCharge + addedCharge;
                }
		else if (pkg = C)
                {
		         baseCharge = 79.95;
		         totalCharge = baseCharge;
                }	
		return charges;

	 }

[buzzdsm]

I tried this above and now get these errors.

----jGRASP exec: javac -g C:\Program Files\Java\jdk1.5.0_15\bin\InternetCharges.java

InternetCharges.java:51: cannot find symbol
symbol : variable A
location: class InternetCharges
if (pkg = A)
^
InternetCharges.java:51: incompatible types
found : char
required: boolean
if (pkg = A)
^
InternetCharges.java:53: cannot find symbol
symbol : variable baseCharge
location: class InternetCharges
baseCharge = 49.95;
^
InternetCharges.java:54: cannot find symbol
symbol : variable addedCharge
location: class InternetCharges
addedCharge = (hours - 40)* 2.00; //2.00 per hour
^
InternetCharges.java:55: cannot find symbol
symbol : variable totalCharge
location: class InternetCharges
totalCharge = baseCharge + addedCharge;
^
InternetCharges.java:55: cannot find symbol
symbol : variable baseCharge
location: class InternetCharges
totalCharge = baseCharge + addedCharge;
^
InternetCharges.java:55: cannot find symbol
symbol : variable addedCharge
location: class InternetCharges
totalCharge = baseCharge + addedCharge;
^
InternetCharges.java:57: cannot find symbol
symbol : variable B
location: class InternetCharges
else if (pkg = B)
^
InternetCharges.java:57: incompatible types
found : char
required: boolean
else if (pkg = B)
^
InternetCharges.java:59: cannot find symbol
symbol : variable baseCharge
location: class InternetCharges
baseCharge = 69.95;
^
InternetCharges.java:60: cannot find symbol
symbol : variable addedCharge
location: class InternetCharges
addedCharge = (hours - 80) * 1.00; //1.00 per hour
^
InternetCharges.java:61: cannot find symbol
symbol : variable totalCharge
location: class InternetCharges
totalCharge = baseCharge + addedCharge;
^
InternetCharges.java:61: cannot find symbol
symbol : variable baseCharge
location: class InternetCharges
totalCharge = baseCharge + addedCharge;
^
InternetCharges.java:61: cannot find symbol
symbol : variable addedCharge
location: class InternetCharges
totalCharge = baseCharge + addedCharge;
^
InternetCharges.java:63: cannot find symbol
symbol : variable C
location: class InternetCharges
else if (pkg = C)
^
InternetCharges.java:63: incompatible types
found : char
required: boolean
else if (pkg = C)
^
InternetCharges.java:65: cannot find symbol
symbol : variable baseCharge
location: class InternetCharges
baseCharge = 79.95;
^
InternetCharges.java:66: cannot find symbol
symbol : variable totalCharge
location: class InternetCharges
totalCharge = baseCharge;
^
InternetCharges.java:66: cannot find symbol
symbol : variable baseCharge
location: class InternetCharges
totalCharge = baseCharge;
^
InternetCharges.java:68: cannot find symbol
symbol : variable charges
location: class InternetCharges
return charges;
^
20 errors

----jGRASP wedge2: exit code for process is 1.
----jGRASP: operation complete.

[Zosden]

public double getCharges()
	 {
	 		
	 	if (pkg.equals('A'))
                {
		     baseCharge = 49.95;
		     addedCharge = (hours - 40)* 2.00;  //2.00 per hour
		     totalCharge = baseCharge + addedCharge;
                }
		else if (pkg.equals('B'))
                {
		      baseCharge = 69.95;
		      addedCharge = (hours - 80) * 1.00;  //1.00 per hour
		      totalCharge = baseCharge + addedCharge;
                }
		else if (pkg.equals('C'))
                {
		         baseCharge = 79.95;
		         totalCharge = baseCharge;
                }	
		return charges;

	 }

You also never declared any of those variables.

[buzzdsm]

Don't give up on me.

public double getCharges()
	 {
	 double baseCharge;
	 double addedCharge;
	 double totalCharge;
	 			
	 	if (pkg.equals('A'))
                {
		     baseCharge = 49.95;
		     addedCharge = (hours - 40)* 2.00;  //2.00 per hour
		     totalCharge = baseCharge + addedCharge;
                }
		else if (pkg.equals('B'))
                {
		      baseCharge = 69.95;
		      addedCharge = (hours - 80) * 1.00;  //1.00 per hour
		      totalCharge = baseCharge + addedCharge;
                }
		else if (pkg.equals('C'))
                {
		         baseCharge = 79.95;
		         totalCharge = baseCharge;
                }	
		return charges;

	 }

InternetCharges.java:54: char cannot be dereferenced
if (pkg.equals('A'))
^
InternetCharges.java:60: char cannot be dereferenced
else if (pkg.equals('B'))
^
InternetCharges.java:66: char cannot be dereferenced
else if (pkg.equals('C'))
^
InternetCharges.java:71: cannot find symbol
symbol : variable charges
location: class InternetCharges
return charges;
^
4 errors

[Zosden]

instead of char use string and instead of 'A' use "A".

[buzzdsm]

instead of char use string and instead of 'A' use "A".

Just to be clear, everywhere where I have "char pkg" I should replace with "string pkg"
and then make the changes to a that you mentioned?

[Zosden]

yeah a b and c.

[buzzdsm]

Thanks a ton for all your help. I'm now down to one error. Here is the error and the code.

InternetCharges.java:72: variable Charges might not have been initialized
return Charges;
^
1 error

public class InternetCharges
{
	private String pkg;   			//Customers package
	private double hours;		//Number of hours used
	
	/**
	 *The constructor uses two parameters to accept
	 *arguments: p and h. The value in p is assigned to
	 *the pkg field and the value in h is assigned to
	 *the hours field. The InternetCharges method is called
	 */
	 
	 public InternetCharges(String p, double h)
	 {
	 	pkg=p;
		hours=h;
	 }

   /**
	 *The getPkg method returns the pkg field
	 */
	 
	 public String getPkg()
	 {
	 	return pkg;
	 }
	 
	/**
	 *The getHours method returns the hours field
	 */
	 
	 public double getHours()
	 {
	 	return hours;
	 }
	 
	/**
	 *The getCharges method returns thestringges field.
	 */
	 
public double getCharges()
	 {
	 double baseCharge;
	 double addedCharge;
	 double totalCharge;
	 double Charges;
	 			
	 	if (pkg.equals("A"))
                {
		     baseCharge = 49.95;
		     addedCharge = (hours - 40)* 2.00;  //2.00 per hour
		     totalCharge = baseCharge + addedCharge;
                }
		else if (pkg.equals("B"))
                {
		      baseCharge = 69.95;
		      addedCharge = (hours - 80) * 1.00;  //1.00 per hour
		      totalCharge = baseCharge + addedCharge;
                }
		else if (pkg.equals("C"))
                {
		         baseCharge = 79.95;
		         totalCharge = baseCharge;
                }	
		return Charges;

	 }
	 }

[pao]

Basically the value charges that you declare in getCharges is not initalised, as the error states.

As you only set this value in a conditional statement (if) there is a chance that if none of those conditions is met then your variable charges will not actually point to a value.

I don't know what is best for your program, you could assign a value like -1 to charges and test for this value after your if statements have finished and throw an exception if the value is this.

[buzzdsm]

Figured it out with all your help. Thank you.

[Zosden]

mark this thread as solved then.