Need help with java while loop

[sammyboy78]

I'm trying to create a program that continuously asks for user input until the user inputs "stop" for employee name which will terminate the program. I have compiled the following code but when the program runs through the second time it skips the user input for the employee name and goes directly to number of hours worked. What am I doing wrong?

// Weekly pay calculator
// This program will calculate weekly pay amount for an employee when given hours worked and rate of pay
import java.util.Scann er;

public class Pay2
{
//main method
public static void main( String args[])
{
//create Scanner for obtaining inputs from user
Scanner input = new Scanner( System.in );

double hours; //hours worked
double rate; // rate of pay
String employeeName; //name of worker
double pay; // product of hours and rate
String stop;

boolean empName = false;

while ( !empName )
{

System.out.prin tf( "Enter employee name: " ); //prompt
employeeName = input.nextLine( ); //read employee name from user
System.out.prin tln();

if(employeeName .equals("stop") )
{empName = true;
}
else
{empName = false;
}

System.out.prin tf( "Enter hours worked by %s : ", employeeName ); //prompt
hours = input.nextDoubl e(); //read hours worked
System.out.prin tln();

System.out.prin tf( "Enter rate of pay for %s :$", employeeName ); //prompt
rate = input.nextDoubl e();//read rate of pay
System.out.prin tln();

pay = hours * rate; //multiply hours times rate to get weekly pay

System.out.prin tf( "Employee name: %s \nWeekly pay amount: $%.2f", employeeName, pay); //display name and pay amount
System.out.prin tln();
} //end while
} //end main

} //end class

[dmjpro]

I'm trying to create a program that continuously asks for user input until the user inputs "stop" for employee name which will terminate the program. I have compiled the following code but when the program runs through the second time it skips the user input for the employee name and goes directly to number of hours worked. What am I doing wrong?

// Weekly pay calculator
// This program will calculate weekly pay amount for an employee when given hours worked and rate of pay
import java.util.Scann er;

public class Pay2
{
//main method
public static void main( String args[])
{
//create Scanner for obtaining inputs from user
Scanner input = new Scanner( System.in );

double hours; //hours worked
double rate; // rate of pay
String employeeName; //name of worker
double pay; // product of hours and rate
String stop;

boolean empName = false;

while ( !empName )
{

System.out.prin tf( "Enter employee name: " ); //prompt
employeeName = input.nextLine( ); //read employee name from user
System.out.prin tln();

if(employeeName .equals("stop") )
{empName = true;
}
else
{empName = false;
}

System.out.prin tf( "Enter hours worked by %s : ", employeeName ); //prompt
hours = input.nextDoubl e(); //read hours worked
System.out.prin tln();

System.out.prin tf( "Enter rate of pay for %s :$", employeeName ); //prompt
rate = input.nextDoubl e();//read rate of pay
System.out.prin tln();

pay = hours * rate; //multiply hours times rate to get weekly pay

System.out.prin tf( "Employee name: %s \nWeekly pay amount: $%.2f", employeeName, pay); //display name and pay amount
System.out.prin tln();
} //end while
} //end main

} //end class

It is most probably because of unread enter(next line) character.

Kind regards,
dmjpro.

[r035198x]

I'm trying to create a program that continuously asks for user input until the user inputs "stop" for employee name which will terminate the program. I have compiled the following code but when the program runs through the second time it skips the user input for the employee name and goes directly to number of hours worked. What am I doing wrong?

// Weekly pay calculator
// This program will calculate weekly pay amount for an employee when given hours worked and rate of pay
import java.util.Scann er;

public class Pay2
{
//main method
public static void main( String args[])
{
//create Scanner for obtaining inputs from user
Scanner input = new Scanner( System.in );

double hours; //hours worked
double rate; // rate of pay
String employeeName; //name of worker
double pay; // product of hours and rate
String stop;

boolean empName = false;

while ( !empName )
{

System.out.prin tf( "Enter employee name: " ); //prompt
employeeName = input.nextLine( ); //read employee name from user
System.out.prin tln();

if(employeeName .equals("stop") )
{empName = true;
}
else
{empName = false;
}

System.out.prin tf( "Enter hours worked by %s : ", employeeName ); //prompt
hours = input.nextDoubl e(); //read hours worked
System.out.prin tln();

System.out.prin tf( "Enter rate of pay for %s :$", employeeName ); //prompt
rate = input.nextDoubl e();//read rate of pay
System.out.prin tln();

pay = hours * rate; //multiply hours times rate to get weekly pay

System.out.prin tf( "Employee name: %s \nWeekly pay amount: $%.2f", employeeName, pay); //display name and pay amount
System.out.prin tln();
} //end while
} //end main

} //end class

1.) Please use code tags when posting code
2.) Use input.next(); instead of input.nextLine( ) for reading the name.
3.) Exit the loop when stop is entered otherwise the program probably continues to take in details for an employee named stop!

[sammyboy78]

Ok I've made some suggested changes and it works great. Thanks for the help! Now I have a problem that when I run the program, if I enter a one word name (John) it executes perfectly but if I enter a two word name such as John Smith I get this error message:

C:\Documents and Settings\Sam>ja va Pay2
Enter employee name: John Smith

Enter hours worked by John : Exception in thread "main" java.util.Input MismatchE
xception
at java.util.Scann er.throwFor(Sca nner.java:840)
at java.util.Scann er.next(Scanner .java:1461)
at java.util.Scann er.nextDouble(S canner.java:238 7)
at Pay2.main(pay2. java:32)

Here is my revised code:

// Weekly pay calculator
// This program will calculate weekly pay amount for an employee when given hours worked and rate of pay
import java.util.Scanner;

public class Pay2
{
	//main method
	public static void main( String args[])
	{
		//create Scanner for obtaining inputs from user
		Scanner input = new Scanner( System.in );

		double hours; //hours worked
		double rate; // rate of pay
		String employeeName; //name of worker
		double pay; // product of hours and rate
		String stop;

		boolean empName = true;

		while ( empName )
			{

			System.out.printf( "Enter employee name: " ); //prompt
			employeeName = input.next(); //read employee name from user
			System.out.println();

			if( ! (employeeName.equals("stop")))
			   {

				System.out.printf( "Enter hours worked by %s : ", employeeName ); //prompt
				hours = input.nextDouble(); //read hours worked
				System.out.println();

				System.out.printf( "Enter rate of pay for %s :$", employeeName ); //prompt
				rate = input.nextDouble();//read rate of pay
				System.out.println();

				pay = hours * rate; //multiply hours times rate to get weekly pay

				System.out.printf( "Employee name: %s \nWeekly pay amount: $%.2f", employeeName, pay); //display name and pay amount
				System.out.println();
               }
				else
				{
				  empName = false;
				}
			}//end while

	} //end main

} //end class

[JosAH]

Ok I've made some suggested changes and it works great. Thanks for the help! Now I have a problem that when I run the program, if I enter a one word name (John) it executes perfectly but if I enter a two word name such as John Smith I get this error message: <snip>

That's the trouble with scanners: they do exactly what you've told them to do;
when you're just a *bit* off, they crash in a most horrible way.

Basically you want to read a name (or two, three? names) for an employee
followed by a double representing the number of working hours followed by
the payment rate. Lets handle the tree input parts one by one:

1) one or more names are best read on a single line; the nextLine() method
is best for it; it also reads the <newline> character for you.

2) when you want to read a double value and the user types "foobarbaz" the
scanner will crash (as you have painfully noticed). A Scanner class also has
a 'hasDouble()' method which checks if the next input makes up a valid double.

3) when you have sucessfully read a double number the <newline> character
hasn't been read yet (it wasn't part of that double number).

To keep things simple for now I'd suggest you use 'nextLine()' for the names,
and 'nextDouble()' for the numbers; use a 'nextLine() method again after you've
read the last double for the current employee, that enables the scanner to
read *another* entire line for the name(s) of the next employee. the 'nextLine()'
following the last 'nextDouble()' reads away that <newline> character that was
still unread and obstiptated the input buffer. (that's why it seemed it skipped
reading a next name in your original attempt).

kind regards,

Jos

[sammyboy78]

Thnk you! I changed my input.next() to input .nextLine() and also added a nextLine() statement after my last nextDouble() and it works perfectly! You guys are a Godsend! Thanks a lot! Now to program for only positive inputs for hours and rate...