Arrays in numerical order (without importing array.sort() option)

Question

I would like to sort my two arrays in numerical order. So if I input something like: 96 2 1 42 49 5, it'll give me an output of: 1 2 42 49 96.

How would you do this using a for-loop? I'm trying to implement a basic for-loop to get my numbers to ascend numerically.

Here's the code:

public static void main(String[] args) {

    System.out.println("Input up to '10' numbers for current array: ");

    int[] array1 = new int[10];
    int i;
    int k;
    Scanner scan = new Scanner(System.in);

    for (i = 0; i < 10; i++) {
        System.out.println("Input a number for " + (i + 1) + ": ");
        int input = scan.nextInt();
        if (input == -9000) {
            break;
        } else {
            array1[i] = input;
        }
    }

    System.out.println("\n" + "Array 1: ");

    for (int j = 0; j < i; j++) {

        System.out.println((j + 1) + ": " + array1[j]);
    }

    int[] array2 = new int[i];

    System.out.println("\n" + "Array 2: ");

    for (int j = 0; j < i; j++) {
        array2[j] = array1[j];

        System.out.println((j + 1) + ": " + array2[j]);
    }
    scan.close();

  }
}

Read about [sorting algorithms](http://en.wikipedia.org/wiki/Sorting_algorithm)... — Diego, Mar 11 '15 at 02:45
You will need two nested loops for a simple [bubble-sort](http://en.wikipedia.org/wiki/Bubble_sort). — PM 77-1, Mar 11 '15 at 02:45

score 1 · Accepted Answer · answered Mar 11 '15 at 03:03

Using Bubble Sort. You will be required to use 2 for loops.

Complexity of bubble sort is O(n2)

package com.*;

import java.util.Scanner;

public class Sort {

    public static void main(String[] args) {
        int n, c, d, swap;
        Scanner in = new Scanner(System.in);

        System.out.println("Input number of integers to sort");
        n = in.nextInt();

        int array[] = new int[n];

        System.out.println("Enter " + n + " integers");

        for (c = 0 ; c < n ; c++)
            array[c] = in.nextInt();

        for (c = 0 ; c < (n - 1) ; c++) {
            for (d = 0 ; d < n - c - 1 ; d++) {
                if (array[d] > array[d + 1]) /* For descending order use < */
                {
                    swap = array[d];
                    array[d] = array[d + 1];
                    array[d + 1] = swap;
                }
            }
        }

        System.out.println("Sorted list of numbers");

        for (c = 0 ; c < n ; c++)
            System.out.println(array[c]);
    }
}

output

Input number of integers to sort
5
Enter 5 integers
96
2
1
42
49
Sorted list of numbers
1
2
42
49
96

I still don't get how this works. Can you show me how I can implement the bubble sort with my code? — Jeremy, Mar 11 '15 at 03:20

score -1 · Answer 2 · answered Mar 11 '15 at 02:47

There are numerous sorting algorithms that can address this task. Each algorithm makes a trade-offs between speed and complexity. The simplest sorting algorithm is the bubble sort. Bubble sort is inefficient, but totally reasonable to use if you are dealing with small arrays.

Arrays in numerical order (without importing array.sort() option)

2 Answers2