In this tutorial, we will be using a function to swap array elements in JavaScript/jQuery. We will implement the same objective, using an Array.prototype.
Hence, let's start with the code.
Method 1
Check the code, mentioned below. Here, I have used jQuery version 3.1.0. Inside the $(document).ready() section, we have declared an array and a Swap() function to swap the array elements. We are passing the actual array and the indexes to this function.
  1. <script src="https://code.jquery.com/jquery-3.1.0.js"></script>
  2. <script type="text/javascript">
  4. $(document).ready(function(){
  6. var myArray = [18,3,90,25,2,27,36, 22, 4]; //Declare the array
  7. var testString = ''; // declare a temporary variable to store the sorted array values.
  9. //Declare the function to swap the array elements using a third variable.
  10. //Here we are passing the array indexes as well as the array itself
  11. function Swap(arr,a, b){
  12. var temp;
  13. temp = arr[a];
  14. arr[a] = arr[b];
  15. arr[b] = temp;
  16. }
  18. //Declare the function to sort the array
  19. function Sort(array){
  20. for(var j = 0; j< array.length-1; j++){
  21. for(var k = 1; k< array.length; k++){
  22. if(array[k] < array[k - 1]){
  23. Swap(array,k,k-1) //call the Swap function here
  24. }
  25. }
  26. }
  27. }
  29. //Call the Sort Function with the array declared above
  30. Sort(myArray);
  32. //Loop through the sorted array elements after swapping
  33. for(var i = 0; i < myArray.length; i++){
  34. testString += ", " + myArray[i];
  35. }
  37. alert(testString.substring(2)); // Display the sorted array after swapping
  39. });
  40. </script>
Method 2
In this method, we will implement the Swap() function with the Array.prototype builtin. Check with the code, mentioned below. I have added Swap() function to Array.prototype.
P.S
This method should be avoided while working with multiple JS library, as it may create confusion.
  1. <script src="https://code.jquery.com/jquery-3.1.0.js"></script>
  2. <script type="text/javascript">
  4. $(document).ready(function(){
  6. var myArray = [18,3,90,25,2,27,36, 22, 4];
  7. var testString = '';
  9. //Declare the Swap function with Array.prototype. We are only passing the indexes here.
  10. Array.prototype.Swap = function (x,y) {
  11. var b = this[x];
  12. this[x] = this[y];
  13. this[y] = b;
  14. return this; // return the current array instance.
  15. }
  18. //Declare the sort function
  19. function Sort(array){
  20. for(var j = 0; j< array.length-1; j++){
  21. for(var k = 1; k< array.length; k++){
  22. if(array[k] < array[k - 1]){
  23. array.Swap(k,k-1) // Call the Swap() function like this.
  24. }
  25. }
  26. }
  27. }
  29. //call the Sort() function
  30. Sort(myArray);
  32. for(var i = 0; i < myArray.length; i++){
  33. testString += ", " + myArray[i];
  34. }
  36. alert(testString.substring(2)); // display the sorted array.
  38. });
  39. </script>
I hope, this will be helpful for the beginners in JavaScript. Please comment and provide the feedback, if you like my post. Thank you for reading.