import java.lang.*;
class NewClass
{
public static void main(String args[])
{
String s="null";
for(int x=0;++x<=args.length;)
s+=args[x];
System.out.println(s);
}}

in commandline
java NewClass 32 44

i m getting array index out of bounds exception..can some one explain why?its a very simple program..i dont understand wherez the problem..

you are accessing '\0' character of args
because string.length() returns length including '\0'
:D

bhanuj

thanks bhanuj...i realize that was quite a silly mistake of mine.

we assign the String s="null"
this can treate a string but not a null
we can try this
String s=null;
the for loop is starting with 0 and u can perform x<=
the for loop rewritten
for(int x=1;x<=args.lenth;x++)


K.Mallikarjunarao

just change for loop as follows:

for(int x=0;x<args.length; x++)

I'M WRITING A PROGRAM THAT IS SUPPOSED TO GET THE USER TO ENTER IN A BUNCH OF NUMBERS AND THEN GIVE THEM A CHOICE AS TO WHAT THEY WANT TO CONVERT THE DISTANCE(S)IN METRES BUT I CAN"T GET IT TO WORK YOU SEE THE PROBLEM IS THAT IT KEEPS REPEATING THE INPUT AND DOESN'T STOP CAN ANYONE HELP HERE"S THE CODE: (I'M USING BLUEJ)

import javax.swing.*;
import java.text.*;
public class distance
{
    public static void main(String[] args)
        {
            // declaration of variables
            String numStr, qStr;
            double num, squareNum, cubeNum, metres = 0;
            int q;

                    qStr = JOptionPane.showInputDialog("How many numbers do you want to convert?");
                    q = Integer.parseInt(qStr);

                    double[ ] number = new double[q];


                    for (int index = 0; index < number.length; index++)
                    {
                            numStr = JOptionPane.showInputDialog("Enter number "+index);
                            number[index] = Double.parseDouble(numStr);
                    }

                    for (int index = 0; index < number.length; index++)
                    {
                    String answerStr = JOptionPane.showInputDialog("Metres to convert "+number[index]+
                                    "\n1. Convert to Kilometres"
                                    +"\n2. Convert to Inches"
                                    +"\n3. Convert to Feet"
                                    +"\n4. Exit Program");
                                    int answer = Integer.parseInt(answerStr);

                
                     while (answer != 4) THE PROBLEM IS AROUND HERE SOMWHERE
                        {
                            if (answer == 1)
                            {
                             showKilo(number[index]);
                            }
                            if (answer == 2)
                            {
                             showInch(number[index]);
                            }
                             if (answer == 3)
                             {
                             showFeet(number[index]);
                            }
                        }
                    }
        }

    public static void showKilo(double k)
    {
        double kilometres = k * 0.001;
        JOptionPane.showMessageDialog(null, k+" metres = "+kilometres+" kilometres");
    }

    public static void showInch(double i)
    {
        double inches = i * 39.37;
        JOptionPane.showMessageDialog(null, i+" metres = "+i+" inches");
    }

    public static void showFeet(double f)
    {
        double feet = f * 3.281;
        JOptionPane.showMessageDialog(null, f+" metres = "+f+" feet");
    }

}

Hi,

Try this code, i've modified it.

import javax.swing.*;
import java.text.*;
public class Test
{
    public static void main(String[] args)
        {
            // declaration of variables
            String numStr, qStr;
            double num, squareNum, cubeNum, metres = 0;
            int q;

                    qStr = JOptionPane.showInputDialog("How many numbers do you want to convert?");
                    q = Integer.parseInt(qStr);

                    double[ ] number = new double[q];


                    for (int index = 0; index < number.length; index++)
                    {
                            numStr = JOptionPane.showInputDialog("Enter number "+index);
                            number[index] = Double.parseDouble(numStr);
                    }

                    for (int index = 0; index < number.length; index++)
                    {
                    int answer = 0;
                        do{
                        String answerStr = JOptionPane.showInputDialog("Metres to convert "+number[index]+
                                        "\n1. Convert to Kilometres"
                                        +"\n2. Convert to Inches"
                                        +"\n3. Convert to Feet"
                                        +"\n4. Exit Program");
                           answer = Integer.parseInt(answerStr);

                           if (answer == 1){
                               showKilo(number[index]);
                           }else if (answer == 2){
                                  showInch(number[index]);
                           }else if (answer == 3){
                                  showFeet(number[index]);
                           }
                        }while(answer != 4);
                    }
        }

    public static void showKilo(double k)
    {
        double kilometres = k * 0.001;
        JOptionPane.showMessageDialog(null, k+" metres = "+kilometres+" kilometres");
    }

    public static void showInch(double i)
    {
        double inches = i * 39.37;
        JOptionPane.showMessageDialog(null, i+" metres = "+i+" inches");
    }

    public static void showFeet(double f)
    {
        double feet = f * 3.281;
        JOptionPane.showMessageDialog(null, f+" metres = "+f+" feet");
    }

}


Regards,
Rakesh