Thread: Working with Methods

This is my code:

import javax.swing.JOptionPane ;
import java.util.Date ;
 
 
public class blahblah  {
  // *************************************************************************main
  public static void main(String[] args) {
 
	String province ;
 
	province = getGoodProvinceCode() ;
 
	}// close main
 
 
 
      // *********************************************************************getPST
  public static String getPST(String province) {
 
	final double GST = 0.05 ;
	final double AB_PST = 0.0  ; // AB provincial sales tax
	final double BC_PST = 0.07 ; // BC provincial sales tax
	final double MB_PST = 0.07 ; // MB provincial sales tax
	final double NB_PST = 0.08 ; // NB provincial sales tax
	final double NL_PST = 0.08 ; // NL provincial sales tax
	final double NS_PST = 0.08 ; // NS provincial sales tax
	final double ON_PST = 0.08 ; // ON provincial sales tax
	final double PE_PST = 0.10 ; // PE provincial sales tax
	final double QC_PST = 0.075 ; // QC provincial sales tax
    final double SK_PST = 0.05 ; // SK provincial sales tax
	double pst ;
	double gst ;
	double hst ;
 
	String prov ;
 
	province = getGoodProvinceCode() ;
 
	// find tax rates
    gst = GST ;
    hst = pst = 0. ;
    if ( province.equals("AB") )
      pst = 0. ;
    else if ( province.equals("BC") )
      pst = BC_PST;
    else if ( province.equals("MB") )
      pst = MB_PST;
    else if ( province.equals("NB") ) {
      pst = gst = 0;
      hst = GST + NB_PST ;
    }
    else if ( province.equals("NL") ) {
      pst = gst = 0;
      hst = GST + NL_PST ;
    }
    else if ( province.equals("NS") ) {
      pst = gst = 0;
      hst = GST + NS_PST ;
    }
    else if ( province.equals("ON") )
      pst = ON_PST;
    else if ( province.equals("PE") )
      pst = PE_PST;
    else if ( province.equals("QC") )
      pst = QC_PST;
    else if ( province.equals("SK") )
      pst = SK_PST;
    else
      pst = -1 ;
 
    if ( hst > 0 ) {
		prov = ("H" + hst) ;
	}
	else if ( hst == 0 ) {
		prov = ("P" + pst) ;
	}
	else {
		prov = ("") ;
	}
 
	return prov ;
 
  }// close getPST
 
      // *********************************************************************getGoodProvinceCode
  public static String getGoodProvinceCode() {
 
	  String prompt ;
	  String errorMsg ;
	  String provinceC = "" ;
	  String prov ;
	  String province = "" ;
 
	  boolean inputOk ;
 
    // input province
    prompt = "Enter two-letter province abbreviation (e.g., MB)" ;
    inputOk = false ;
    errorMsg = "" ;
    prov = getPST(province) ;
    while ( ! inputOk ) {
      provinceC = JOptionPane.showInputDialog(null, errorMsg + prompt) ;
      provinceC = provinceC.toUpperCase().trim() ;
      if ( prov.equals("") ) {
        errorMsg = "Input " + provinceC
          + " is not a valid province abbreviation\n" ;
        System.out.println( errorMsg ) ;
	  }
      else {
        inputOk = true ;
      }
    }
 
    return provinceC ;
 
  }// close getGoodProvinceCode
 
}// close class

I get this error:

Exception in thread "main" java.lang.StackOverflowError
	at ChurchAustinA3Q1.getGoodProvinceCode(ChurchAustinA3Q1.java:101)
	at ChurchAustinA3Q1.getPST(ChurchAustinA3Q1.java:48)
	at ChurchAustinA3Q1.getGoodProvinceCode(ChurchAustinA3Q1.java:111)
	at ChurchAustinA3Q1.getPST(ChurchAustinA3Q1.java:48)
	at ChurchAustinA3Q1.getGoodProvinceCode(ChurchAustinA3Q1.java:111)
	...etc...

I think I am getting an error because getGoodProvinceCode() calls getPST(String province), and then getPST(String province) calls getGoodProvinceCode(). I just don't know how to fix this loop.

EDIT/ Is it possible to return a variable in the middle of a method without ending the method at that point?

What you essentially have is a malformed recursive function.

To fix:

Have your main method call getProvince() to get a province, then call getPST() to get the sales tax rate for that province. Remove all calls from getProvince() to getPST() and vise-versa. You'll also need to adjust your methods to not call each other.

No, a method may not return a value and continue running. That would violate the method contract.