Thread: new to java, and need help with assigment

Hi all, i need to make a translater program that translate words. example if u type in hello all it should return ellohsese llasese. it moves the first letter in the words to last and puts sese at the end of the words, then i need to have a way to reverse the method, so if i type in ellohsese llasese it should return hello all.

i have got the program to almost work as i like , the thing is it just works if i type in one word ie hello and returns ellohsese. and i dont really know how to fix it, so if someone could give me some advise to how i can get it to work i would be happy

import javax.swing.*; 
 
public class TransLater { 
 
    public static void main(String[] arg) { 
 
        String val; 
        JOptionPane.showMessageDialog(null, "Welcome to the Translater");
 
        while(true) { 
 
            val = JOptionPane.showInputDialog("1) Translate to  \n2) Translate from");    
 
            if(val.equals("1")) {
 
            	StringBuffer str = new StringBuffer("");
                String indata; 
                char first;                 
                indata = JOptionPane.showInputDialog("Type ur words here:"); 
                str.insert(0,indata); 
                first = str.charAt(0); 
                str.deleteCharAt(0); 
                str.append(first); 
                str.append("sese"); 
 
                JOptionPane.showMessageDialog(null, str);
 
            } 
 
            else if(val.equals("2")) { 
 
            	String indata2; 
 
                indata2 = JOptionPane.showInputDialog("Type ur words here:"); 
 
                while (indata2.endsWith("sese")) { 
                	indata2 = indata2.substring(0, indata2.length() - 4);
                	String last = indata2.substring(indata2.length() -1); 
                	indata2 = indata2.substring(0, indata2.length() -1); 
 
                    JOptionPane.showMessageDialog(null, last + indata2); 
 
 
                    }
 
            } 
 
            else {
            	JOptionPane.showMessageDialog(null, "Wrong selection, try again"); 
            }
 
        } 
 
    } 
 
}

Can you post the output from when the code does not work that shows the problem.
Add comments saying what is wrong with the output and show what the output should be.

You need to get the individual words from the String so you can work on them one by one.
Then you can change them and build a new String with the changed words.
The String class has methods to help you separate the String into separate words. See the split() method.

where in the code should i set it up for it to work?

After you have read in the String that you want to split.

How did you use the split method? It returns an array that you must then go into to get the strings that were split from the original string.

The words array now has the split strings in it. You will need a loop to get them out one by one and do the conversion on each of them.

Add some printlns to the code to show the value of variables as they are set and changed.

You get to the elements of an array by using an index value inside of []s
words[0] is a reference to the first element in the words array.

The elements of an array are items of the same class as the array type:
words[0] is a String.

i got the code working did do the split method wrong :/ the program now works, but i get a Exception in thread "main" java.lang.NullPointerException
at OverSattaren.main(OverSattaren.java:23)
when i close the program and i cant figure out why?

What is the code at the line where the exception occurs?
Can you post the full text of the error message.

Edit your post and change the tags to[code=java]<YOUR CODE HERE>[/code] to get highlighting

What is the value of the val variable? That is the only thing that would cause a NPE with statement you posted.

What is the statement that throws the NPE? You need to find the variable with null value!!!

What is the value of indata when the code in post#20 is executed?

Glad you figured it out.