Sort an array in Java

I'm trying to make a program that consists of an array of 10 integers which all has a random value, so far so good.

However, now I need to sort them in order from lowest to highest value and then print it onto the screen, how would I go about doing so?

(Sorry for having so much code for a program that small, I ain't that good with loops, just started working with Java)

public static void main(String args[])
{
    int [] array = new int[10];

    array[0] = ((int)(Math.random()*100+1));
    array[1] = ((int)(Math.random()*100+1));
    array[2] = ((int)(Math.random()*100+1));
    array[3] = ((int)(Math.random()*100+1));
    array[4] = ((int)(Math.random()*100+1));
    array[5] = ((int)(Math.random()*100+1));
    array[6] = ((int)(Math.random()*100+1));
    array[7] = ((int)(Math.random()*100+1));
    array[8] = ((int)(Math.random()*100+1));
    array[9] = ((int)(Math.random()*100+1));

    System.out.println(array[0] +" " + array[1] +" " + array[2] +" " + array[3]
    +" " + array[4] +" " + array[5]+" " + array[6]+" " + array[7]+" " 
    + array[8]+" " + array[9] );        

}

Solution 1:

Loops are also very useful to learn about, esp When using arrays,

int[] array = new int[10];
Random rand = new Random();
for (int i = 0; i < array.length; i++)
    array[i] = rand.nextInt(100) + 1;
Arrays.sort(array);
System.out.println(Arrays.toString(array));
// in reverse order
for (int i = array.length - 1; i >= 0; i--)
    System.out.print(array[i] + " ");
System.out.println();

Solution 2:

Add the Line before println and your array gets sorted

Arrays.sort( array );

Solution 3:

It may help you understand loops by implementing yourself. See Bubble sort is easy to understand:

public void bubbleSort(int[] array) {
    boolean swapped = true;
    int j = 0;
    int tmp;
    while (swapped) {
        swapped = false;
        j++;
        for (int i = 0; i < array.length - j; i++) {
            if (array[i] > array[i + 1]) {
                tmp = array[i];
                array[i] = array[i + 1];
                array[i + 1] = tmp;
                swapped = true;
            }
        }
    }
}

Of course, you should not use it in production as there are better performing algorithms for large lists such as QuickSort or MergeSort which are implemented by Arrays.sort(array)

Solution 4:

Take a look at Arrays.sort()

Solution 5:

I was lazy and added the loops

import java.util.Arrays;


public class Sort {
    public static void main(String args[])
    {
        int [] array = new int[10];
        for ( int i = 0 ; i < array.length ; i++ ) {
            array[i] = ((int)(Math.random()*100+1));
        }
        Arrays.sort( array );
        for ( int i = 0 ; i < array.length ; i++ ) {
            System.out.println(array[i]);
        }
    }
}

Your array has a length of 10. You need one variable (i) which takes the values from 0to 9.

for ( int i = 0  ; i < array.length ;   i++ ) 
       ^               ^                   ^
       |               |                   ------  increment ( i = i + 1 )
       |               |
       |               +-------------------------- repeat as long i < 10
       +------------------------------------------ start value of i


Arrays.sort( array );

Is a library methods that sorts arrays.