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?

Answer 1

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

Answer 2

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.

Answer 3

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.