[eagles94]

I am making a spanish verb conjugator gui. Basically, you enter a spanish verb like "hablar" (to talk) and press the conjugate button. It will conjugate the verb in spanish present tense. The problem is that to conjugate into the tense
I need to drop the ar in habl(ar) and replace it with the letter o to get hablo. How do I chop off the last two letters?

This is what I tried to do. I placed hablar in an array called verbs and then made another array that had two less places then the verbs array. I then used a for loop to fill each position of the new array except for the last two characters since its length will exceed it. It still keeps out printing Hablar though!

[teQuiero]

i think its more better if you create an a list of pastTense and presentTense then compare it to the text. rather than droping or removing txt.

[eagles94]

so what your saying is to basically create another array of already filled verbs with tense changes and just print that out. If so that was my original plan but wouldnt chopping off the last two letters and just addin a letter be faster and less lines?? Or is it actually complex to do that?

[Mylo]

You could do something like String myWord = "Hablar"; System.out.println(myWord.substring(0, myWord.length() - 2) + 'o');

I'm not familiar with Spanish, but I assume the same replace 'ar' with 'o' will not work every time. If that is the case, I would probably have a map of them as teQuiero suggested.

Also, show us your code for your attempt, we will be able to point out what you did incorrectly.

[eagles94]

alright let me try that and if it doesnt work at all, I'll post the code. thanks.

[eagles94]

Okay now im lost. I keep getting nullpointerexception error. Here is the code.

import javax.swing. *;
import java.awt.*;
import java.awt.event.*;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;


public class Conjugator extends JPanel
{
String[] regularAR = new String[5];
String[] regularER = new String[5];
String s, myWord;
private JLabel title, output;
private JTextField input;
private int i;
public Conjugator()
{
	
	
	regularAR[0] = "comprar";
	regularAR[1] = "bailar";
	regularAR[2] = "cantar";
	regularAR[3] = "hablar";
	regularAR[4] = "trabajar";
	
	regularER[0] = "beber";
	regularER[1] = "correr";
	regularER[2] = "romper";
	regularER[3] = "aprender";
	regularER[4] = "deber";
	
	setLayout(new BorderLayout());


   JPanel titlepanel = new JPanel();
	titlepanel.setLayout(new FlowLayout());
	add(titlepanel, BorderLayout.NORTH);
		
	JPanel ippanel = new JPanel();
	ippanel.setLayout(new FlowLayout());
	add(ippanel, BorderLayout.CENTER);
	
	JPanel dppanel = new JPanel();
	dppanel.setLayout(new FlowLayout());
	add(dppanel, BorderLayout.SOUTH);

	
	title = new JLabel("Spanish Verb Conjugator");
	title.setFont(new Font("Serif", Font.BOLD, 20));
	titlepanel.add(title, BorderLayout.CENTER);
	
	input = new JTextField("Enter common Spanish Verb", 20);
	input.setHorizontalAlignment(SwingConstants.LEFT);
	ippanel.add(input);
	
	output = new JLabel("");
	dppanel.add(output);
	
}

public void update()
{
	 s = input.getText();
	
	for(int i = 0; i < regularAR.length; i++);{
	if(s.equals(regularAR[i])) {
    myWord = s;
	} }
	String j = m.substring(0,myWord.length()-2);
        String one = "o";
	output.setText("Yo: " +j+one);
	 
		
	
    }

  }
 

[Ryano121]

A NullPointerException on which line?

[eagles94]

on line 70 with the string j = substring blah blah

[Ryano121]

m.substring(0,myWord.length()-2);

where is m defined?

[eagles94]

oops. Its supposed to be myWord.substring

but even then it still shows up as a null pointer exception

[nick2price]

post the exception

[Ryano121]

Best thing you can do is set a breakpoint on line 70. Then watch the value of 's' and 'myWord'. You will probably see that s is set to null. Therefore pointing to a problem with the input.

[eagles94]

here is the exception

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at Conjugator.update(Conjugator.java:70)
at StudyTool$presentListener.actionPerformed(StudyTool.java:46)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
at java.awt.Component.processMouseEvent(Component.java:6288)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
at java.awt.Component.processEvent(Component.java:6053)
at java.awt.Container.processEvent(Container.java:2041)
at java.awt.Component.dispatchEventImpl(Component.java:4651)
at java.awt.Container.dispatchEventImpl(Container.java:2099)
at java.awt.Component.dispatchEvent(Component.java:4481)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4577)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
at java.awt.Container.dispatchEventImpl(Container.java:2085)
at java.awt.window.dispatchEventImpl(window.java:2478)
at java.awt.Component.dispatchEvent(Component.java:4481)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:643)
at java.awt.EventQueue.access$000(EventQueue.java:84)
at java.awt.EventQueue$1.run(EventQueue.java:602)
at java.awt.EventQueue$1.run(EventQueue.java:600)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
at java.awt.EventQueue$2.run(EventQueue.java:616)
at java.awt.EventQueue$2.run(EventQueue.java:614)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:613)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)

[teQuiero]

seems fine to me when i tried compiling after fixing

String j = myWord.substring(0,myWord.length()-2);

[GetSet]

eagles94, on 01 April 2012 - 10:27 AM, said:

oops. Its supposed to be myWord.substring

but even then it still shows up as a null pointer exception

If you haven't, you need to instantiate your strings.

That is,

String j = new String();

Then,

j = substring yada yada;

later in the code.