JavaScript Bubble & Insertion sort for objects in an array

Question

I'm trying to bubble sort by price and insert sort by name but I'm confused about how to print the sorted list. Do I just console.log because I tried that and it just printed the array but without it being sorted? Am I supposed to return something? (pls don't mind the formatting I'm new here sorry!)

    //Class 

      class Shoe{
          constructor(name, price, type) {
          this.name = name;
          this.price = price;
          this.type = type;
          }
     }

    // list of objects
    var shoes = [
        new Shoe('Nike AirMax 90', '120', 'Casual'),
        new Shoe('Jordan Retro 1', '110', 'Casual'),
        new Shoe('Jadon Doc Martens', '250', 'Seasonal boots'),
        new Shoe('Adidas X Ghosted', '110', 'Athletic'),
        new Shoe('Nike Vapourmax Flyknit', '250', 'Casual'),
        new Shoe('Aldo Loafers', '130', 'Formal'),
        new Shoe('Timberlands', '199', 'Seasonal boots'),
        new Shoe('Converse High Tops', '70', 'Casual'),
        new Shoe('Converse Low Tops', '80', 'Casual'),
        new Shoe('Adidas NMDs', '110', 'Athletic'),
        new Shoe('Heels', '130', 'Formal'),
        new Shoe('Nike AirForce', '150', 'Casual')
    ];

    // bubble sort
       function bubbleSort(shoes) {
         var swapped;
         do {
           swapped = false;
              for (var i=0; i < shoes.length-1; i++) {
                 if (shoes[i].price > shoes[i+1].price) {
                    var temp = shoes[i];
                    shoes[i] = shoes[i+1];
                    shoes[i+1] = temp;
                    swapped = true;
                 }
              }
          } while (swapped);
        }

       // insertion sort
       function insertionSort(shoes) {
          let a = shoes.length;
              for (let i = 1; i < a; i++) {
              // Choosing the first element in our unsorted subarray
                  let first = shoes[i];
        // The last element of our sorted subarray
                  let l = i-1; 
                  while ((l > -1) && (first.type < shoes[l].type)) {
                       shoes[l+1] = shoes[l];
                       l--;
                  }
                  shoes[l+1] = first;
               }
           return shoes;
        }

Any help is really appreciated, thank you!

after that do I print it out? because I want to check if it sorted the array @RandyCasburn — 28space_junkiee, Oct 28 '20 at 22:01
No, no you don't. That isn't correct, since arrays in js are (effectively) passed by reference, you're mutating the calling data. You don't need to return, if you don't want to. — zcoop98, Oct 28 '20 at 22:06
so what do you suggest I should do to check if my array is sorted? @zcoop98 — 28space_junkiee, Oct 28 '20 at 22:10
It sounds like taking a copy and returning it might work better if you still want to keep the unsorted array around to compare. If you're just looking to check if the array is sorted, you'll need another algorithm, which doesn't have to be complex. [Here's a relevant answer](https://stackoverflow.com/a/18111261/11047824) I found. — zcoop98, Oct 28 '20 at 22:14
ok thank you, I think I'll keep it like this but I have to do a computational complexity analysis for it do you think it'd be too complicated to keep it this way for the analysis? @zcoop98 — 28space_junkiee, Oct 28 '20 at 22:18
Tbh, it's been a long while since I've done that kind of analysis, but since your functions contain just the sort, I *think* it should be fairly straightforward. Best of luck! :) — zcoop98, Oct 28 '20 at 22:19

score 0 · Answer 1 · answered Oct 28 '20 at 22:11

Sort functions can either sort the input data by mutating/ altering the input, or by taking and returning a sorted copy, which leaves the original untouched. Either type is an acceptable way to do things.

In your example, both of your sorts mutate the passed in data, so while they can return the array as a convenience (like your insertion sort already does), bear in mind that the original array is still changed regardless of whether the returned value is recorded.

A problem you're running into here that I can see, however, is actually about string conversion- you need to convert your prices to numbers to compare them properly. At the moment, you're performing string comparison.

There's more than a few ways to do this, but I personally like the unary plus.

class Shoe {
  constructor(name, price, type) {
    this.name = name;
    this.price = price;
    this.type = type;
  }
}

var shoes = [
  new Shoe('Nike AirMax 90', '120', 'Casual'),
  new Shoe('Jordan Retro 1', '110', 'Casual'),
  new Shoe('Jadon Doc Martens', '250', 'Seasonal boots'),
  new Shoe('Adidas X Ghosted', '110', 'Athletic'),
  new Shoe('Nike Vapourmax Flyknit', '250', 'Casual'),
  new Shoe('Aldo Loafers', '130', 'Formal'),
  new Shoe('Timberlands', '199', 'Seasonal boots'),
  new Shoe('Converse High Tops', '70', 'Casual'),
  new Shoe('Converse Low Tops', '80', 'Casual'),
  new Shoe('Adidas NMDs', '110', 'Athletic'),
  new Shoe('Heels', '130', 'Formal'),
  new Shoe('Nike AirForce', '150', 'Casual')
];

function bubbleSort(shoes) {
  var swapped;
  do {
    swapped = false;
    for (var i = 0; i < shoes.length - 1; i++) {
    
      // Must convert prices to numbers,
      // otherwise they get compared as strings
      if (+shoes[i].price > +shoes[i + 1].price) {
        var temp = shoes[i];
        shoes[i] = shoes[i + 1];
        shoes[i + 1] = temp;
        swapped = true;
      }
    }
  } while (swapped);
  return shoes;
}

bubbleSort(shoes);
console.log('Bubble Sort:\n', shoes);

score 0 · Answer 2 · answered Oct 29 '20 at 02:48

Not sure of the reason you are writing sorts from scratch. Don't get me wrong, I like to 'roll my own' on a lot of stuff, but if you want to do a sort you can just do:

shoes.sort(function (a, b) {return a.price - b.price});

As for your displaying your results, I usually just make a simple html page with a div element and a button. When I click the button I have my function fill in the div using the div's innerText property with the result. Just remember when sending objects or arrays to an display, you will probably want to use JSON.stringify so you get the actual contents instead of just

[object Object],[object Object],[object Object]

JavaScript Bubble & Insertion sort for objects in an array

2 Answers2