Sort array from smallest to largest using java

Question

I'm supposed to create an array and sort the numbers from smallest to largest. Here is what I have so far:

public class bubbleSort {

public static void sort (int [] arrayName){
    int temp;
    for (int i = 0; i < arrayName.length-1; i++)
    {
        if(arrayName[i] > arrayName[i+1])
        {
            temp=arrayName[i];
            arrayName[i]=arrayName[i+1];
            arrayName[i+1]=temp;
            i=-1;
        }
    }
}

public static void main(String[] args) {
    int [] arrayName = new int[10]; 
    for (int i = 0; i < arrayName.length; i++) { 
      arrayName[i] = (int)(Math.random()*100); 
    } 

    System.out.println(sort(arrayName)); 
}
}

I am getting an error on the last line where I'm trying to print it out. What am I doing wrong?

what is the error you are getting?

kosa
– kosa

2012-01-19 19:23:48 +00:00
Commented Jan 19, 2012 at 19:23 — kosa
– kosa, Commented Jan 19, 2012 at 19:23
Your sort 'function' isn't returning anything

Dan
– Dan

2012-01-19 19:25:07 +00:00
Commented Jan 19, 2012 at 19:25 — Dan
– Dan, Commented Jan 19, 2012 at 19:25

Alex · Accepted Answer · 2012-01-19 19:23:20Z

15

Your sort(int[] array) method returns nothing. It is void, therefore you cannot print its return.

answered Jan 19, 2012 at 19:23

Alex

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4 Comments

Alex Over a year ago

I suggest running through arrayName with a for-loop and printing out each index.

Bryan Over a year ago

Ah, so I need to change it to int instead of void. How do I get it to return all numbers of the array as oppose to just the value in temp or some other individual value?

Alex Over a year ago

The way you have it is fine, your variable arrayName is now sorted. You just need to rifle through its values now, and print them each :)

Louis Wasserman Over a year ago

Just call sort(array) on its own line, and then print out the array elements one by one.

Eric B. · Accepted Answer · 2012-01-20 19:17:31Z

3

You need to iterate over the array and print out each value. You cannot just println(<array>). Instead, try:

// sort the array
sort(arrayName);
for( int sortedValue : arrayName )
  System.out.println( sortedValue );

That will iterate over each element in the array and print it out.

You can also use commons-lang's ArrayUtils.toString() method to do this all automatically for you, but I am assuming that since this is a homework assignment, you cannot just use external libraries to do your work for you.

edited Jan 20, 2012 at 19:17

answered Jan 19, 2012 at 21:11

Eric B.

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Comments

Gaston Flores · Accepted Answer · 2013-07-20 18:35:14Z

Maybe you can use lambdaj (download here,website), this library is very powerfull for managing collections (..list,arrays), the following code is very simple and works perfectly:

import static ch.lambdaj.Lambda.on;
import static ch.lambdaj.Lambda.DESCENDING;
import static ch.lambdaj.Lambda.sort;
import java.util.Arrays;
import java.util.List;

public class Test {
    public static void main(String[] args) {
        List<Integer> numberList =  Arrays.asList(4,8,2,3,4,1,13,2,5);

        List<Integer> sortedList = sort(numberList, on(Integer.class));
        System.out.println(sortedList); //shows ascending list

        sortedList = sort(numberList, on(Integer.class), DESCENDING);
        System.out.println(sortedList); //shows descending list
    }
}

This code shows:

[1, 2, 2, 3, 4, 4, 5, 8, 13]
[13, 8, 5, 4, 4, 3, 2, 2, 1]

In one line you can sort a list, this is a simple example but with this library you can resolve more.

sort(numberList, on(Integer.class));

You must add lambdaj-2.4.jar to your project. I hope this will be useful.

Note: This will help you assuming you can have alternatives to your code.

Mangoose · Accepted Answer · 2013-07-20 18:10:56Z

1

For learning purpose writing your own sort function is fine but for production code always use java API Arrays.sort

answered Jul 20, 2013 at 18:10

Mangoose

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Comments

UtopiaLtd · Accepted Answer · 2013-04-18 22:05:31Z

0

You need to change your sort method--it is returning nothing.

public static void is for a method where you are not returning anything. Try this:

public static int sort (int[] arrayname)

edited Apr 18, 2013 at 22:05

UtopiaLtd

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answered Apr 18, 2013 at 21:39

CBH

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user2507212 · Accepted Answer · 2013-07-20 18:05:54Z

0

public static int[ ] arraySortUp( int[ ] intArray )
{
        int toSwap, indexOfSmallest = 0;
        int i, j, smallest;

        for( i = 0; i < intArray.length; i ++ )
        {               

            smallest = Integer.MAX_VALUE;

            for( j = i; j < intArray.length; j ++ )
            {
                if( intArray[ j ] < smallest )
                {
                    smallest = intArray[ j ];
                    indexOfSmallest = j;
                }                   
            }

            toSwap = intArray[ i ];
            intArray[ i ] = smallest;
            intArray[ indexOfSmallest ] = toSwap;
        }

        return intArray;
}

answered Jul 20, 2013 at 18:05

user2507212

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Comments

A. Radek Martinez · Accepted Answer · 2015-09-03 14:08:40Z

0

This is the "cleaner" way to do this (I think):

    public static void main(String[] args) throws IOException {

    int[] array = {1,4,2,8,4,7,5 /*put in the numbers you want to sort*/};

    Arrays.sort(array); /*You will need to import this function*/

    for (int i = 0; i < array.length; i++) {
       System.out.println(array[i]);
    }

    }

Hope this help!

answered Sep 3, 2015 at 14:08

A. Radek Martinez

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Comments

Adeel Asghar · Accepted Answer · 2016-08-31 11:13:39Z

Array Sorting without using built in functions in java ......just make new File unsing this name -> (ArraySorting.java) ..... Run the Project and Enjoy it !!!!!

import java.io.*;
import java.util.Arrays;
import java.util.Scanner;
public class ArraySorting 
{
 public static void main(String args[])
 {
    int temp=0;   
    Scanner user_input=new Scanner(System.in);
    System.out.println("enter Size elements...");
    int Size=user_input.nextInt();

    int[] a=new int[Size];
    System.out.println("Enter element Of an Array...");
    for(int j=0;j<Size;j++)
    {
        a[j]=user_input.nextInt();
    }     
    for(int index=0;index<a.length;index++)
    {
        for(int j=index+1;j<a.length;j++)
        {
             if(a[index] > a[j] ) 
             {
                 temp = a[index];
                 a[index] = a[j];
                 a[j] = temp;
             }
        }
    }
    System.out.print("Output is:- ");
    for(int i=0;i<a.length;i++)
    {
        System.out.println(a[i]);
    }

}

}

Adeel Asghar · Accepted Answer · 2016-09-02 12:11:16Z

-2

Create File with java Extentation.i-e(ArraySorting.java) then Paste the Code....

import java.io.*;
import java.util.Arrays;
import java.util.Scanner;
public class ArraySorting 
{


public static void main(String args[])
{
       Scanner user_input=new Scanner(System.in);

       System.out.println("enter Size elements...");
       int Size=user_input.nextInt();

       int[] a=new int[Size];
       System.out.println("Enter element Of an Array...");
        for(int j=0;j<Size;j++)
        {
            a[j]=user_input.nextInt();
        }

        Arrays.sort(a);       
        for(int index=0;index<a.length;index++)
        {
            System.out.println(a[index]);
        }

}

}

edited Sep 2, 2016 at 12:11

answered Aug 31, 2016 at 10:32

Adeel Asghar

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4 Comments

LordWilmore Over a year ago

I'm only guessing, but I think the OP was trying to write their own sorting algorithm rather than using an off-the-shelf solution.

Adeel Asghar Over a year ago

This is a simple Java Coding Dude :/ ....try to this Link....stackoverflow.com/questions/8931977/…. thankx---

LordWilmore Over a year ago

Quite. I would imagine it's somebody that's learning how to program, and when it becomes 'simple' to them then they should use library methods as you have, but jumping to the answers section is never a good way to learn

Adeel Asghar Over a year ago

ok i understant.. Arrays.sort(a); is a library of java for sorting.....

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