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I cant seem to get this to work.. Any pointers?
Code:Object[] options= {"Show Amortization","Enter Another Loan","Exit Program"};
}
a=JOptionPane.showConfirmDialog(null, "Would you like to see the amortization of the current loan?");
JOptionPane.YES_NO_CANCEL_OPTION;
JOptionPane.Question_MESSAGE;
if("Show Amortization"==yes{contniue};
else if("Enter Another Loan"==no){main();
return;}
else if ("Exit Prgram");{System.exit(0)
};
Quote:
I cant seem to get this to work.. Any pointers?
This single statement has almost too many errors:Code:if("Show Amortization"==yes{contniue};
Comparing Strings with ==
No ending ) for the condition
continue misspelled
I'll leave the rest for the next guy. This is too easy.
yea i have no idea whats going on with this.... is there even a way to go back to the top of a program or keep going with the rest of the program?
The code you posted will not compile. Until it compiles, it will not go anywhere.Quote:
is there even a way to go back to the top of a program
Use a loop to allow execution to go back to an earlier point in the program.
how would a loop start over a program? every thing i have read on loops and if statements dont seem to work.. Do i start the loop at the beginning of the program? then once i get to where i want it to continue or start over add the string?
Loops don't start a program. They are used allow you to repeatedly execute a group of statements.
In pseudo code:
Code:begin loop
do some stuff
if (...) continue; // go back to the beginning of the loop
do some more stuff
// at this point the execution goes back to the top of of the loop (or it can test a condition and exit the loop)
end loop
damn.. im still drawing a blank.... this seems to hard of a acquirement for only doing java for about a week or so... I dont even know where to start.
in order to start a loop do i have to declare and int value, or have a statement that allows it to count?
Depends on what kind of loop. There are more than one.Quote:
to start a loop do i have to
You need to find a tutorial that describes how to write a java program, including loops.
Ok so i have read and read and watch videos... Still not fully understanding this... With the code below i am getting these exceptions:
continue outside of loop;
cannot find symbol method ConfirmOption(<nulltype>,java.lang.String,int);
Am i close?
Code:cont=JOptionPane.ConfirmOption(null,"Would you like to see the amoritization of current loan?",
JOptionPane.YES_NO_OPTION);
if(cont.equals(true))
{continue;}
And do i place it inside the amortization loop like this?
Code://below is the loop
p=1;
balance=loan;
for(int month=0;month<(years*12);month++)
cont=JOptionPane.ConfirmOption(null,"Would you like to see the amoritization of current loan?",
JOptionPane.YES_NO_OPTION);
if(cont.equals(true))
{continue;}
else(JOptionPane.)
{
interest=balance*interest_mo;
//System.out.println("interest "+interest);
principal=payments-interest;
//System.out.println("principal "+ principal);
System.out.println("For Payment: " +p++ );
System.out.println( String.format("Principal paid is: $ %.2f", + principal));
balance=balance-principal;
System.out.println( String.format("Remaining balance is: $ %.2f",
+ balance));
}
System.exit(0);
}
Where is the loop statement? There are several:Quote:
continue outside of loop;
for(...) { }
while(cond) { }
do{} while()
What does the API doc for the JOptionPane say? Does it have a ConfirmOption() method?Quote:
find symbol method ConfirmOption(<nulltype>,java.lang.String,int);
Read into loops here: The while and do-while Statements (The Java™ Tutorials > Learning the Java Language > Language Basics)
A do while loop may work great for you if the line of code must run at least once and has no specific amount of times it can be run.
oh.. I give up. I cant find anything on making loops with a joption... I just cant seem to get my head around how an if statement works with joption to ask a user to continue the program or return to the main, and setting a loop up for this to happen seems impossible... Thanks for the help any ways
Can you write a description in English of the steps you want your program to do. Write short statements.
For example
When you get a design, then write the loop.Code:begin loop
get input from user
test if valid input
if not valid input, continue at the top of the loop
do something with the input
if there is no more stuff to do - break out of the loop
end loop - here we will loop back to the start of the loop
When you get a loop, write code to get the input.
When you get the input, write a test for it.
etc
I'm curious, if you're only just starting Java. How are you learning it that is making you use GUI right off the bat?
But Norm is correct, you should always have some pseudocode or a flow chart before you start programming that way you know how you want your program to work.
Well, its an assignment, but the requirements were to make a program that calculates a mortgage, then run a loop to show amortization, then/and prompt the user to either enter another loan amount or continue with the amortization or exit the program. I got the first two parts working flawlessly, with some big help from norm. But i cant seem to figure out how to ask the user to start from the top of the program (enter another amount) or continue the program (show the amortization of the current imputed loan). So this is where i get lost, should the loop start within or right before the amortization loop? If i write a continue statement asking the user to continue, will it not only be for that loop its in, not the loop that shows the amortization? how would i combine two loops? I dont even know where to start, i mean i have the concept of what needs to happen, but i dont know enough about java to fully get the extent of how the syntax works. Im waaay better with SQL, that is kiddy stuff compared to this though. I was thinking that there is just a confirm dialog that can either keep going with the program or just return to main to start over... But i was totally wrong with that.
Are you using console input for the amount or are you building a gui?
Im using a GUI, here is the full code. /**/ is where i am trying to build this part im stuck at.
Code:
import javax.swing.*;
public class MortgageApp3 {
public static void main(String args[])
{
double loan,
interest_yr,
years,
interest_mo,
loan_pmts,
payments,
new_balance,
interest,
interestamt,
principal,
principalamt,
payamt,
balance;
int p;
//Above is all the varaibles used for calculations
String loanamt,
interest_peryr,
yearstot,
pay_amt,
cont,
restart;
//The above declares the strings for the program
loanamt= JOptionPane.showInputDialog("Enter Loan Amount"); //Obtains input from user for loan amount
interest_peryr=JOptionPane.showInputDialog("Enter the Interest Percentage: Example 5.6"); //Obtains input from user for interest %
yearstot=JOptionPane.showInputDialog("Enter Loan Period in Years"); //Obtains input for length of loan
// Below is the code to parse stings into doubles
loan=Double.parseDouble(loanamt);
interest_yr=Double.parseDouble(interest_peryr);
years=Double.parseDouble(yearstot);
interest_mo = (interest_yr/12.0)/100.0; // Turns percent whole numbers into decimals
loan_pmts= years * 12; //Gets total amount of months the loan will last after user inputs length of loan in years
payments = (loan*interest_mo/(1- Math.pow((1+interest_mo),-loan_pmts))); //Loan calculation
JOptionPane.showMessageDialog (null, String.format( "Your payment is: $ %.2f ", + payments)); //Shows payment with 2 decimal places
principalamt= payments - (loan *interest_mo); //calculates principle
JOptionPane.showMessageDialog(null, String.format( "your prinicple paid is: $ %.2f ", + principalamt)); //shows principle with 2 decimal places
interestamt= payments-principalamt ; //calculates interest
JOptionPane.showMessageDialog(null, String.format( "your interest paid is: $ %.2f ", + interestamt)); //shows interest with 2 decimal places
/*do(cont=JOptionPane.ConfirmOption(null,"Would you like to see the amoritization of current loan?",
while JOptionPane.YES_NO_OPTION);
(cont.equals(true)));
{continue;};
if(cont.equals(false));
{return main};*/
//below is the loop
p=1;
balance=loan;
for(int month=0;month<(years*12);month++)
{
interest=balance*interest_mo;
//System.out.println("interest "+interest);
principal=payments-interest;
//System.out.println("principal "+ principal);
System.out.println("For Payment: " +p++ );
System.out.println( String.format("Principal paid is: $ %.2f", + principal));
balance=balance-principal;
System.out.println( String.format("Remaining balance is: $ %.2f",
+ balance));
}
System.exit(0);
}
}
tweaked it some:
getting illegal start of expression exceptionCode:cont=JOptionPane.ConfirmOption(null,"Would you like to see the amoritization of current loan?",
JOptionPane.YES_NO_OPTION);
while (cont.equals(true)));
{continue;};
if (cont.equals(false));
{return main;};
Quote:
I dont even know where to start,
I suggested earlier that you write out the steps you want to do in a list of simple steps.Quote:
i have the concept of what needs to happen
Don't try to solve ALL of the problems at the same time. Isolate each of them to a simple problem and solve that problem. In some cases write a small program to work on that problem alone. When you solve it you can merge the logic into the big program.