Reverse Array Error

[Mr.Nasty]

I need help with trying to create a array where you enter the the number of integers you want in the array, you enter the numbers, and it prints the reverse of the numbers. I keep getting errors everytime I atempt to run this program.


public class RA{

public static void main(String[] args) {
int numofarry = 0;
int[] a;

String numofarry = JOptionPane.showInputDialog(null,
"Enter the list length:",
"Project 4 Input", JOptionPane.QUESTION_MESSAGE);

numofarry = Intger.parseInt(numofarry);

a = new int[numofarry];

reverse(a);

System.out.println("The reversal is ");

for (int i = 0; i < a.length; i++){
String aString = JOptionPane.showInputDialog(null,
"Enter a number:",
"Project 4 Input", JOptionPane.QUESTION_MESSAGE);
a[i] = Integer.parseInt(aString);


}
System.out.print(a[i] + " ");
}

public static int[] reverse(int[] a) {


int[] newList = new int[a.length];

for (int i = 0; i < a.length; i++)
newList[i] = a[a.length - 1 - i];

a = newList;
}
}

[buntine]

You cant cast a String to an int, also, Strings are immutable. You will have to use a seperate variable.
Also, you cannot use the same name for two variables in the same scope.

int arrSize;
int[] a;

String numofarry = JOptionPane.showInputDialog(null,
                   "Enter the list length:",
                   "Project 4 Input", JOptionPane.QUESTION_MESSAGE);

arrSize = Integer.parseInt(numofarry);
a       = new int[numofarry];
...

Furthermore, you spelt Integer as Intger.

Another thing, why are you calling reverse() before your adding data to the array? Your actually passing an empty array.

Regards.

[buntine]

Another few things I picked up on, you cant access the looping variable i outside of the for block, it is out of scope and Java does not recognise it.

And, in your reverse function, you actually have to return a value. Otherwise, you will get a nasty error.

public static int[] reverse(int[] a) 
{
   int[] newList = new int[a.length];
   for (int i = 0; i < a.length; i++)
      newList[i] = a[(a.length - 1) - i];
   return newList;
}

Regards.

[Mr.Nasty]

My only problem now is that I can only get it yo output the orginal array but not the reverse. Help please

import javax.swing.JOptionPane;

public class pro41{

public static void main(String[] args) {
int numofarry=0;
int[] a;

String numofarryString = JOptionPane.showInputDialog(null,
"Enter the list length:",
"Project 4 Input", JOptionPane.QUESTION_MESSAGE);

numofarry = Integer.parseInt(numofarryString);
a = new int[numofarry];



System.out.println("The reversal is ");

for (int i = 0; i < a.length; i++){
String aString = JOptionPane.showInputDialog(null,
"Enter a number:",
"Project 4 Input", JOptionPane.QUESTION_MESSAGE);

a[i] = Integer.parseInt(aString);
System.out.print(a[i] + " ");
reverse(a);


}



}


public static int[] reverse(int[] a)
{
int[] newList = new int[a.length];
for (int i = 0; i < a.length; i++)
newList[i] = a[(a.length - 1) - i];
return newList;
}

}

[buntine]

Thats because your printing out the array items before you are reversing the array. And your reversing the array several times.

...
   System.out.println("The reversal is ");

   for (int i = 0; i < a.length; i++)
   {
      String aString = JOptionPane.showInputDialog(null,
                       "Enter a number:",
                       "Project 4 Input", JOptionPane.QUESTION_MESSAGE);

      a[i] = Integer.parseInt(aString);
   }

   reverse(a);
   printArray(a);
}

public static int[] reverse(int[] a)
{
   int[] newList = new int[a.length];
   for (int i = 0; i < a.length; i++)
      newList[i] = a[(a.length - 1) - i];
   return newList;
}

private void printArray(int [] arr)
{
   for (int i=0; i<arr.length; i++)
   {
      String delim = (i == (arr.length-1)) ? "" : ", ";
      System.out.println(arr[i} + delim);
   }
}

Regards.