Sorting names and using JOptionPane to show output

Question

So my code so far is this...

      import javax.swing.*;
        public class TestNo2{
          public static void main(String[] args){
            String[] nameNum = new String[0];
            int numberNames;
            JTextField inputName = new JTextField(5);
              JPanel nameWindow = new JPanel();
                nameWindow.add(new JLabel("How many names would you like to sort?"));
                nameWindow.add(inputName);

            int numNames = JOptionPane.showConfirmDialog(null, nameWindow
                ,"Accept and sort list of students."
                ,JOptionPane.OK_CANCEL_OPTION);
            if(numNames == JOptionPane.OK_OPTION){

              String numNamesS = inputName.getText();
              numberNames = Integer.parseInt(numNamesS);
              nameNum = new String[numberNames];


              for(int counterOne=0;counterOne<nameNum.length;counterOne++){
                for(int counterTwo=1;counterTwo<=nameNum.length;counterTwo++){
                  nameNum[numberNames] = JOptionPane.showInputDialog(null
                    ,"Enter the name of student "+counterTwo
                    ,"Name Input"
                    ,JOptionPane.QUESTION_MESSAGE);
                }   
              }      
            }           
          } 
        }

There's no error when I build it but when I run the program, I would only be allowed to enter one name then the error occurs.

This is the error that shows up.

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 3 at TestNo2.main(TestNo2.java:23)

Thank you for your time in reading this.

Jaskaranbir Singh · Accepted Answer · 2015-12-06T06:01:23.647

for(int counterTwo=1;counterTwo<=nameNum.length;counterTwo++){

should be:

for(int counterTwo=1;counterTwo < nameNum.length;counterTwo++){

Because the expression counterTwo<=nameNum.length causes the array to exceed its bounds (remember that actual length of array starts from zero and is 1 Less than actual length you specified.

So if you have an array defined like:

someArray[] something = {1,2,3,4,5,6};

The value of something.length would be 6. But the actual length is 5 (Counting as: 0,1,2,3,4,5).

And why do you have two loops for just gettings names and adding to String Array? Just one is enough...

for(int counterOne=0;counterOne<nameNum.length;counterOne++){
    nameNum[counterOne] = JOptionPane.showInputDialog(null
                        ,"Enter the name of student "+(counterOne+1)
                        ,"Name Input"
                        ,JOptionPane.QUESTION_MESSAGE);
}

And then sort the array nameNum with whatever method you plan to use.

Thanks for the answer. Although you corrected my mistake, the error is still present. the "ArrayIndexOutOfBoundsException" still shows. Thanks in advance. — Halcyon, Dec 06 '15 at 01:48

Sorting names and using JOptionPane to show output

1 Answers1