Javascript getter methods seems to not work

Question

Hi everyone I've just started javascript recently and I am trying to learn about classes and objects but I ran into a small bump that I could not get through so here is my code

class bubbleSorter{
  constructor(/*params*/){
  //some fields
  }
  #bubbleSorter = () =>{
  //some code
  }

  getBubbleSorter = () =>{
    this.#bubbleSorter();
  }
}

let obj = new bubbleSorter(/*params*/);

console.log(obj.getBubbleSorter());

so this is an example of my code. whenever I try to log the getter method it does not quite work but when I call the bubbleSorter method instead --Assuming I remove the # symbol-- it magically works I do not know why is that happening I tried making bubbleSorter public then calling it inside the getBubbleSorter it still does not work

Because they don't get `this` passed to them, they retain the original `this` from when they were defined. — Barmar, Jul 01 '21 at 20:00
"*whenever I try to log the getter method it does not quite work*" what do you mean? Your `getBubbleSorter()` method doesn't return anything, so it always implicitly produces `undefined`. That's common behaviour for all functions. If your `#bubbleSorter()` is supposed to return a value, then you need `return this.#bubbleSorter();` inside `getBubbleSorter()`. If it's not that, you need to explain what "doesn't work" means here. — VLAZ, Jul 01 '21 at 20:06
@Barmar It Still does not work even though i changed it to normal functions — An aspiring Scientist, Jul 01 '21 at 20:11
@Barmar "*they retain the original this from when they were defined*" which would be the object creation, so `this` will point to the created instance. The values should be correct in this case. Unless the constructor swaps out `this` for some other instance. https://jsbin.com/qonudesalu/1/edit?js,console — VLAZ, Jul 01 '21 at 20:13
Please post a [mcve] and explain what the code is supposed to do. — Barmar, Jul 01 '21 at 20:13
@VLAZ Oh, right. The linked question is about methods in object, not methods in classes. — Barmar, Jul 01 '21 at 20:14

score 0 · Answer 1 · answered Jul 01 '21 at 20:16

0

getBubbleSorter calls this.#bubbleSorter but doesn't return the value, causing the function to return undefined.

answered Jul 01 '21 at 20:16

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score 0 · Answer 2 · answered Jul 01 '21 at 20:27

it looks like you aren't returning anything in your example. Specifically for

getBubbleSorter = () =>{
  this.#bubbleSorter();
}

If you change it to

getBubbleSorter = () =>{
  return this.#bubbleSorter();
}

I think you'll start getting what you expect. What your example currently is doing at the end is the equivalent of

console.log(() => {}());

right now it's executing a function that has no return value, so it logs out undefined. Once you add that return above now you will be logging the result of your private getter.

Javascript getter methods seems to not work

2 Answers2