How to check for change in array while change is via javascript

Question

I want to know if there is a simple, clean way to listen for an array change in an array in Javascript.

I was attempting to use jQuery's change function but soon realized that it only works when the change is made in the HTML. I need to check if a change is made in Javascript, not HTML.

Possible duplicate of [Listening for variable changes in JavaScript](https://stackoverflow.com/questions/1759987/listening-for-variable-changes-in-javascript) — FeaturedSpace, May 31 '19 at 19:24

score 1 · Answer 1 · answered May 31 '19 at 19:28

simple

Proxys can get quite messy when used for heavier lifting, and are limited when it comes to detecting adding or removing fields from objects, but they should work well for your use case. (mdn)

let array = new Proxy([], {
  set: (obj, prop, value) => {
    obj[prop] = value;
    if (prop === 'length')
      console.log(`array length changed to ${value}`);
    else
      console.log(`set index ${prop} to ${value}`);
    return true;
  }
});

array[5] = 3;
array.push(1);
array[0] = 10;
console.log(array);

score 0 · Answer 2 · answered May 31 '19 at 19:23

0

Yes, object.watch (it's non-standard though). Here's my implementation that works in every current major browser.

Listening for variable changes in JavaScript

answered May 31 '19 at 19:23

FeaturedSpace

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3
18

thank you but I think I've figured out an even simpler solution to the problem in my particular case. I do wish to look in to proxies and such in the future though – Procode238 May 31 '19 at 19:52
No problem! I am always happy to assist! – FeaturedSpace May 31 '19 at 20:29

How to check for change in array while change is via javascript

2 Answers2