display array

[Walt Bryant]

Howdy,
I am taking a java class. We are to the point of learning about arrays. In the textbook there is an example given to sort an array in descending order. I can get the code to compile but I can't figure out how to display the sorted array. The code is:

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

int [ ] usersNumbers = {7, 14, 3, 88, 2};
final int NUM_ENTERED = 5;
 
int temp = 0;
int a = 0;
int b = 0;
int comparisonsToMake = usersNumbers.length -1;
for (a = 0; a < usersNumbers.length - 1; ++a)
{
    for (b = 0; b > usersNumbers.length - 1; ++b)
   {
if (usersNumbers [b] < usersNumbers [b + 1])
{
temp = usersNumbers [b];
usersNumbers [b] = usersNumbers [b + 1];
usersNumbers [b + 1] = temp;
}
   }
  --comparisonsToMake;
}


}
}

I have tried System.out.println(usersNumbers [b] );
With this output statement I get the number 7.
I am trying to get 88 14 7 3 2

Thanks for any help.

[edit]Add code tags. CR[/edit]
[ November 15, 2008: Message edited by: Campbell Ritchie ]

[Ernest Friedman-Hill]

Hi Walt,

Welcome to JavaRanch!

In Java 1.5 and up (which you're almost certainly using) there are some handy "toString()" routines in the java.util.Arrays class:

System.out.println(Arrays.toString(usersNumbers));

would do the trick. But you might want to do it yourself, just for learning's sake, in which case the right thing to do is write a little method that uses a "for" loop to print the value of each array element, one at a time, following each by a space.

[Walt Bryant]

Thanks for your help. I think I'm getting close. This is what I've got so far:

import java.util.*;
public class Test
{
public static void main (String [ ] args)
{
int [ ] usersNumbers = {7, 14, 3, 88, 2};
final int NUM_ENTERED = 5;
 
int temp;
int a;
int b = 0;

int comparisonsToMake = usersNumbers.length -1;
for (a = 0; a < usersNumbers.length - 1; ++a)
{
    for (b = 0; b > usersNumbers.length - 1; ++b)
   {

if (usersNumbers [b] < usersNumbers [b + 1])
{
temp = usersNumbers [b];
usersNumbers [b] = usersNumbers [b + 1];
usersNumbers [b + 1] = temp;
}
   }
  --comparisonsToMake;
   }
sortDescending (usersNumbers, usersNumbers.length);        
}
 
public static void sortDescending (int array [ ], int num)
{
int x;
System.out.print ("The array sorted in descending order is: ");
for (x = 0; x < num; ++x)
System.out.print (" " + array [x]);

}
 
}

The array does not appear to be going through the code that sorts it into descending order. The output from the method is:
The array sorted in descending order is: 7 14 3 88 2
Is it because of where the method call is placed?

[Ernest Friedman-Hill]

This line:

for (b = 0; b > usersNumbers.length - 1; ++b)

says "set b to 0; then, while b is larger than usersNumbers.length - 1, do the following..." Should be "<", not ">", yes?

In any case, it's pretty confusing that the code to sort the data is there in main(), but there's a method called "sortDescending()" which, rather than sorting anything, displays the array's contents. Shouldn't the method be called, "display()" or "printArray()" or something along those lines?

[Walt Bryant]

Thank you, Thank You, Thank You. Should be "<", not ">" was the problem. I also changed sortDescending ( ) to printArray ( ). I think I understand now. I really do appreciate your help.