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JavaScript: Sorting Algorithm Comparison

In this article we present a visualizaion of four different JavaScript DHTML sorting classes all of which have been described in more detail in previous articles.

Sorting Algorithm Visualization

Below you will see four scrambled versions of the same image. When you use the controls below to 'solve' the puzzles they will each use a different sorting algorithm as indicated - Bubble, Insertion, Shell and Quick Sort - to rearrange the pieces.

You can watch in real time as the sorting takes place and see an updating counter of the number of steps taken so far - where a 'step' is the process of exchanging two puzzle pieces.

583
624
335
989
627
514
551
809
175
346
799
191
242
318
757
462
134
461
259
524
583
527
613
174
59
933
5
70
236
774
73
336
74
768
727
367
544
576
796
133
848
363
330
552
281
882
421
725
77
475
328
268
349
337
861
506
932
456
818
934
84
284
519
927
267
438
4
28
257
547
94
213
887
46
448
26
53
742
613
581
664
229
559
319
508
546
541
855
515
905
146
413
320
13
949
962
362
355
419
577
BubbleSort - 0 steps
968
651
534
612
457
258
277
323
681
306
435
42
147
661
86
658
533
427
728
81
42
54
387
185
437
352
905
693
120
422
59
907
582
761
229
730
404
106
479
65
940
185
252
118
661
955
678
846
680
793
515
600
728
827
497
626
912
276
842
343
813
505
1000
458
542
130
639
736
539
270
56
406
816
59
946
771
570
916
159
780
774
757
930
824
113
894
375
208
325
35
967
134
468
890
42
756
186
391
905
401
InsertionSort - 0 steps
211
317
465
104
53
570
797
744
566
452
461
319
156
121
359
836
212
941
668
812
832
864
413
325
718
81
409
862
201
846
770
110
857
169
780
177
365
162
447
743
992
950
668
152
980
143
532
659
118
375
551
614
111
251
58
736
175
371
874
938
701
326
729
464
215
240
997
239
700
216
447
713
99
856
669
342
724
890
908
873
609
872
840
253
554
57
556
223
612
835
855
839
186
433
705
440
197
626
716
793
ShellSort - 0 steps
293
880
279
593
572
238
842
269
251
499
601
141
360
157
201
741
930
900
224
513
979
937
230
833
515
674
205
959
167
44
484
670
215
701
509
781
579
376
645
818
467
915
698
981
245
568
704
962
77
996
508
369
461
552
431
428
228
651
401
811
875
732
116
838
290
982
171
654
772
238
460
23
64
375
33
228
273
745
414
161
379
442
219
445
298
776
479
963
388
10
885
174
828
245
61
318
804
873
875
589
QuickSort - 0 steps
Controls 1) Select an image; 2) Click 'SOLVE'. * images generated by Stable Diffusion and Midjourney

All of the sorting is powered by JavaScript in your web browser so there is no load at all on the web server. There is also only a single background image being used each time - they haven't been sliced up into smaller squares for the puzzle.

While there are other methods for shuffling and sorting values, the advantage of DHTML sorting - rearranging actual HTML elements within the DOM - is that it preserves any event handlers or other dynamically assigned properties that may have been assigned to the elements.

This is possible because we are working with a 'live' NodeList which means that "changes in the DOM automatically update the collection."

Comparison of Results

As expected, the Bubble Sort and Insertion Sort algorithms are relatively slow requiring a large number of steps to solve the puzzle. This is mainly down to the fact that they can only swap adjacent squares.

The Insertion Sort and Quick Sort algorithms are significantly faster thanks to their more advanced algorithms requiring only a fraction of the number of steps each time to reconfigure the puzzle pieces.

We generally use the Shell Sort algorithm which, despite being slightly slower, is a stable sort, whereas Quick Sort is unstable (a sorting algorithm is said to be stable "when two objects with equal keys appear in the same order in sorted output as they appear in the input unsorted array").

What do we use if for?

Apart from these fascinating visualizations we typically use JavaScript DHTML sorting when presenting tabular data. It allows us to have the table contents sorted by various values on demand without needing to re-request data from the web server.

You can see some examples of this in earlier articles on the subject. The code used here for the visualization has been adapted slightly to insert a delay, but is otherwise identical to the code presented there.

We were able to insert delays into the sorting process by converting the exchange step to use a generator function which is then called repeatedly by setInterval. Generators have the effect of allowing you to 'pause' and 'resume' execution within a function.

Another interesting use case would be maintaining a 'pole position' graphic where race data was being dynamically inserted into the page and the task was to keep the list in the right order - perhaps with a touch of animation.

If you find a use for this code in your website or project please let us know using the comments button below.

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