converting words to numbers like a phone. i.e. 1800CALLMEE = 1-800-225-5544

Please Help! I can't get this program to run correctly...
I have 2 questions so far:

1.) How do i get my program to print each number instead of just the very last number? I was thinking maybe it had something to do with the break;'s. this is the first time i've ever used a switch statement.

2.) Why do I keep getting a "NullPointerException" error? it says "java.lang.NullPointerException
at PhoneClientDialog.main(PhoneClientDialog.java:10)"

Here's my student class code:

Code Java:

---

public class Phone
{
    private String word;
    private String number;
 
    public Phone(String word)
    {
        this.word = word;
        this.setNumber();
    }
 
    private void setNumber()
    {
       //Assign number to empty string to avoid null. 
       this.number = ("");
 
       //Convert characters in word to digits.
       int index = 0;
 
       while (index < this.word.length())
       {   
               //Places digits in number.
               switch(this.word.toLowerCase().charAt(index))
               {
                       //#2
                       case 'a': this.number = "2"; break;
                       case 'b': this.number = "2"; break;
                       case 'c': this.number = "2"; break;
                       //#3
                       case 'd': this.number = "3"; break;
                       case 'e': this.number = "3"; break;
                       case 'f': this.number = "3"; break; 
                       //#4
                       case 'g': this.number = "4"; break;
                       case 'h': this.number = "4"; break;
                       case 'i': this.number = "4"; break;
                       //#5
                       case 'j': this.number = "5"; break;
                       case 'k': this.number = "5"; break;
                       case 'l': this.number = "5"; break;
                       //#6
                       case 'm': this.number = "6"; break;
                       case 'n': this.number = "6"; break;
                       case 'o': this.number = "6"; break;
                       //#7
                       case 'p': this.number = "7"; break;
                       case 'r': this.number = "7"; break;
                       case 's': this.number = "7"; break;
                       //#8
                       case 't': this.number = "8"; break;
                       case 'u': this.number = "8"; break;
                       case 'v': this.number = "8"; break;
                       //#9
                       case 'w': this.number = "9"; break;
                       case 'x': this.number = "9"; break;
                       case 'y': this.number = "9"; break;
               }
         index++;
       }        
    }
 
    //public method that returns number.
    public String toString()
    {
        return this.number;
    }
 
 
}

---

and here is my parent class code:

Code Java:

---

import javax.swing.JOptionPane;
 
public class PhoneClientDialog
{
   public static void main(String[] args)
   {
      String input = JOptionPane.showInputDialog(
         "Complete the phone number with a word (quit terminates program): 1-800-");
 
	  while(!(input.equalsIgnoreCase("quit")))
	  {
		  Phone myPhone = new Phone(input);
		  input = JOptionPane.showInputDialog("The actual phone number is 1-800-" + myPhone + '\n' +
         	"Complete the phone number with a word (quit terminates program): 1-800-");
	  }
 
      System.exit(0);
   }
}

---

the parent class is the one throwing codes but my professor wrote it and we're not allowed to touch it. i would e-mail him but it's the weekend. :/

Words to numbers.

Well, entering anything in JOptionPane will be taken as a String.

To get it to ints,

int x = Integer.parseInt(StringFromJOptionPane);

I think I have an idea.

For every case, call the toString().

Right now, it'll just do it for the last number due to your while loop.

If you want it every time:

Code java:

---

while (index < this.word.length())
       {  
               //Places digits in number.
               switch(this.word.toLowerCase().charAt(index))
               {
                       //#2
                       case 'a': this.number = "2"; 
this.toString();
break;
                       case 'b': this.number = "2"; 
this.toString();
break;
// you get the idea
 
// if you want to print out to, just call prinltln(toString())
 
}

---

Okay, I'll take a crack at the first part of your question.

If it seems to be only displaying the very last character, I think that would be because each time you run through your for loop, you are over-writing the previous entry by saying

Code :

---

this.number = "#";

---

What if you tried this instead:

Code :

---

this.number += "#";

---

or, if you prefer

Code :

---

this.number = this.number + "#";

---

Hope this helps.

Quote:

---

Originally Posted by mystikaljester

Okay, I'll take a crack at the first part of your question.

If it seems to be only displaying the very last character, I think that would be because each time you run through your for loop, you are over-writing the previous entry by saying

Code :

---

this.number = "#";

---

What if you tried this instead:

Code :

---

this.number += "#";

---

or, if you prefer

Code :

---

this.number = this.number + "#";

---

Hope this helps.

---

That worked! Yay! Thank you so much! You're the bomb! :D

My evaluate method in OperatorNode is having a problem. Data is being updated. Sorry for losing my patience, but I do have a rapidly approaching deadline.