{"id":16,"date":"2018-11-15T18:01:00","date_gmt":"2018-11-15T18:01:00","guid":{"rendered":""},"modified":"2019-02-12T23:35:47","modified_gmt":"2019-02-12T22:35:47","slug":"how-bubble-sort-algorithm-works-implementation-in-java","status":"publish","type":"post","link":"https:\/\/kindsonthegenius.com\/blog\/how-bubble-sort-algorithm-works-implementation-in-java\/","title":{"rendered":"How Bubble Sort Algorithm Works (Implementation in Java)"},"content":{"rendered":"

This would be a very simple explanation with the program in Java on how the Bubble Sort Algorithms works.<\/p>\n

Bubble Sort works by iterating through the elements of the array and doing pairwise swap of adjacent elements that are out of order.<\/p>\n

<\/div>\n

We would examine the program in Java and then explain it line by line. The we would actually run the program using Netbeans IDE to see how it works.<\/p>\n

The java program is explained as follows: There would be three functions in addition to the main methods<\/p>\n

BubbleSort():<\/b> This is the function that performs the sorting on an array. This function takes an array as parameter.<\/p>\n

 <\/p>\n

<\/p>\n

    \/\/THE BUBBLESORT FUNCTION IN JAVA<\/span>\r\n    public<\/span> static<\/span> void<\/span> BubbleSort<\/span>(<\/span>int<\/span>[]<\/span> a)<\/span>\r\n    {<\/span>\r\n        int<\/span> i,<\/span> j;<\/span>\r\n        int<\/span> N =<\/span> a.<\/span>length<\/span>;<\/span><\/pre>\n
for<\/span>(<\/span>j=<\/span>N–<\/span>1<\/span>;<\/span> j><\/span>0<\/span>;<\/span> j–)<\/span> {<\/span>
\nfor<\/span>(<\/span>i=<\/span>0<\/span>;<\/span> i<<\/span>j;<\/span> i++){<\/span>
\nif<\/span>(<\/span>a[<\/span>i]><\/span> a[<\/span>i+<\/span>1<\/span>])<\/span>
\nswap(<\/span>a,<\/span> i,<\/span> i+<\/span>1<\/span>);<\/span>
\n}<\/span>
\n}<\/span>
\n}<\/span><\/p>\n
Listing 1: BubbleSort function<\/p>\n
<\/ins>
\nSwap():<\/b> This function performs a pairwise swap of two array elements. It take three parameters: the first is the array, the second and third are the indices of the elements to be swapped.<\/p>\n
<\/p>\n
    \/\/FUNCTION TO PERFORM SWAP OF TWO ITEMS<\/span>\r\n    public<\/span> static<\/span> void<\/span> swap<\/span>(<\/span>int<\/span>[]<\/span> ar,<\/span> int<\/span> x,<\/span> int<\/span> y)<\/span>\r\n    {<\/span>\r\n        int<\/span> k =<\/span> ar[<\/span>x];<\/span>\r\n        ar[<\/span>x]<\/span> =<\/span> ar[<\/span>y];<\/span>\r\n        ar[<\/span>y]<\/span> =<\/span> k;<\/span>\r\n    }<\/span><\/pre>\n
Listing 2: Swap Function<\/p>\n
 <\/p>\n
Display(): <\/b>This function displays the elements of the array to the output by looping through the array elements and calling System.out.println().<\/p>\n
<\/p>\n
    \/\/FUNCTION TO DISPLAY ARRAY ITEMS TO THE OUTPUT<\/span>\r\n    public<\/span> static<\/span> void<\/span> Display<\/span>(<\/span>int<\/span> a[])<\/span>\r\n    {<\/span>\r\n        int<\/span> i=<\/span>0<\/span>;<\/span>\r\n        while<\/span>(<\/span>i !=<\/span> a.<\/span>length<\/span>)<\/span>\r\n        {<\/span>\r\n            System.<\/span>out<\/span>.<\/span>println<\/span>(<\/span>a[<\/span>i]);<\/span>\r\n            i++;<\/span>\r\n        }<\/span>       \r\n    }<\/span><\/pre>\n
Listing 3: Swap Function<\/p>\n
 <\/p>\n
Main():<\/b> Runs the program by calling the each of the functions.<\/p>\n
    \/\/MAIN PROGRAM<\/span>\r\n    public<\/span> static<\/span> void<\/span> main<\/span>(<\/span>String[]<\/span> args)<\/span> {<\/span>\r\n      int<\/span> a[]<\/span> =<\/span> {<\/span>5<\/span>,<\/span>7<\/span>,<\/span>3<\/span>,<\/span>8<\/span>,<\/span>0<\/span>,<\/span>2<\/span>};<\/span>    \/\/INITIALIZE AN ARRAY WE ARE GOING TO SORT<\/span>\r\n      Display(<\/span>a);<\/span>                 \/\/DISPLAY THE UNSORTED ARRAY<\/span>\r\n      BubbleSort(<\/span>a);<\/span>              \/\/SORT THE ARRAY USING BUBBLESORT     <\/span>\r\n      System.<\/span>out<\/span>.<\/span>println<\/span>(<\/span>\"The Sorted list is given below:\"<\/span>);<\/span>\r\n      Display(<\/span>a);<\/span>                 \/\/DISPLAY THE SORTED ARRAY<\/span>\r\n    }<\/span><\/pre>\n
Listing 4: Main Program<\/p>\n
 <\/p>\n
This short video explains how to put everything together and run it in Netbeans<\/p>\n