Basic Java Array Question

JonT

Ok, very new to Java. The goal here was to read in 10 integers into an array, then print the array elements out in reverse order.

Can't seem to get it to work though.

I guess my problem is with the second "for" loop here, not with the array really.

Any help much appreciated, and I bet it will take about a second for someone to point out what I've done wrong.

public class MyArray
{
public static void main(String[] args)
{

int numbers[10]; //declare array "numbers" which will hold 10 integers


//create array and assign its address to the variable "numbers"

numbers = new int[10];

//read in integers

System.out.println("Please enter first integer:");

for (int i=0; i<numbers.length; i++)
{ numbers = Console.readInt();
System.out.println("Please enter next integer:");
}

//print out array elements in reverse

for (int i=9; i<=numbers.length; i--)
{
System.out.println(" " + numbers + " ");
}
}
}

DonkeyStyle \o/

Well I don't know Java, but on the 2nd for loop, since you're deincrementing, the exiting condition should be when the counter hits zero... not when it's less or equal to the size of the array.

And surely there's some array function you can use to re-order the array instead of just counting back though it?

marco_polo

      for (int i=numbers.length-1; i>0; i--)
      {  
         System.out.println(" " + numbers[i] + " ");
      }

Just change the second for loop to this.

veryangryman

//Your welcome! Go in peace my son

import java.awt.*;
import javax.swing.*;
import java.util.*;
import java.io.*;


public class MyArray
{
public static void main(String[] args)
{

int numbers[]; //declare array "numbers" which will hold 10 integers


//create array and assign its address to the variable "numbers"

numbers = new int[10];

//read in integers
int x=1;

System.out.println("Please enter first integer:");

for (int i=0; i<numbers.length; i++)
{
numbers = x;
System.out.println(" " + numbers + " ");
x+=1;


}

//print out array elements in reverse

for (int i=9; (i<=numbers.length) && (i>0); i--)
{
System.out.println(" " + numbers + " ");
}
}
}

Giblet

That second loop may never execute if there are 8 elements in the array, and there's a bunch of imports you don't need...

for (int i=numbers.length-1; i>=0; i--)
{  
     System.out.println(" " + numbers[i] + " ");
}

JonT

Thanks all!
Giblet, yours is the most correct code, is it not?

since

for (int i=numbers.length-1; i>=0; i--)
{
System.out.println(" " + numbers + " ");
}

will also print out the array element at position 0, where as

for (int i=numbers.length-1; i>0; i--)
{
System.out.println(" " + numbers + " ");
}

would only print out those at positions 9 to 1.

Am I right?

Thanks again people!

marco_polo

Yep my bad. Should have been i >=0