# Cannot add mesh to my array

**URL:** <https://talk.code3dgames.com/t/cannot-add-mesh-to-my-array/641>\
**Category:** Uncategorized\
**Created:** [September 18, 2023, 10:45pm UTC](https://talk.code3dgames.com/t/cannot-add-mesh-to-my-array/641 "2023-09-18T22:45:16Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![Moldy-Mango](https://talk.code3dgames.com/user_avatar/talk.code3dgames.com/moldy-mango/32/70_2.png) [@Moldy-Mango](https://talk.code3dgames.com/u/Moldy-Mango)\
**Post date:** [September 18, 2023, 10:45pm UTC](https://talk.code3dgames.com/t/cannot-add-mesh-to-my-array/641/1 "2023-09-18T22:45:16Z")

</div>

So I was going to make a game where you’re a rocket flying through space (inspired by Chapter 5). Here’s some of my code:

[https://www.code3dgames.com/3de/#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](https://www.code3dgames.com/3de/#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)

The JavaScript console has an error:  
Uncaught TypeError: Cannot read properties of undefined (reading ‘push’)  
at createPlanet (code.html:46:13)  
at addPlanets (code.html:40:7)  
at code.html:33:3

I really can’t figure out what’s going on here, because I tried the push method in the JavaScript console and it went smoothly without any errors.

Thanks for helping! 😁 😁

---

<div class="post-metadata">

**Author:** ![chris](https://talk.code3dgames.com/user_avatar/talk.code3dgames.com/chris/32/5_2.png) [@chris](https://talk.code3dgames.com/u/chris)\
**Post date:** [September 18, 2023, 10:58pm UTC](https://talk.code3dgames.com/t/cannot-add-mesh-to-my-array/641/2 "2023-09-18T22:58:51Z")

</div>

At the top of the code, you’ve started a code outline, which is good:

```auto
  var gameOver = false;  
  addPlanets();

```

In that code outline, you’ve started the `gameOver` variable as `false`, which makes sense since the game probably hasn’t started at this point. Next you start adding planets in the `addPlanet()` function.

In that function, you create 100 planets using the `createPlanet()` function:

```auto
  function addPlanets() {
    if (gameOver) return;
    for (var i=0; i<100; i++) {
      createPlanet();
    }
  }

```

And in the `createPlanet()` function, you set the size to a random number and then… you’ve got a mistake. You add that size to the `planets` variable with `push`:

```auto
  function createPlanet() {
    var size = r(50);
    planets.push(size);
    // ...
  }

```

There are two problems here:

1. You probably want to add planets to the list of items in the `planets` variable – not the size of the planets
2. You haven’t defined what `planets` is.

To fix #2, go back to the code outline at the top and define `planets` as an empty list:

```auto
  var gameOver = false;  
  var planets = [];
  
  addPlanets();

```

I think you already know how to fix #1 because you already have the right code for this later in your `createPlanet()` function – it’s just commented out right now. So remove the line that currently does `planets.push(size)` and un-comment the other two lines at the bottom of the `createPlanet()` function.

Hopefully that all makes sense. If you have any other questions / problems, please ask 🙂

-Chris

---

<div class="post-metadata">

**Author:** ![Moldy-Mango](https://talk.code3dgames.com/user_avatar/talk.code3dgames.com/moldy-mango/32/70_2.png) [@Moldy-Mango](https://talk.code3dgames.com/u/Moldy-Mango)\
**Post date:** [September 24, 2023, 12:26am UTC](https://talk.code3dgames.com/t/cannot-add-mesh-to-my-array/641/3 "2023-09-24T00:26:48Z")

</div>

Okay, so I tried that, but the same problems are coming up in the JavaScript console:

Uncaught TypeError: Cannot read properties of  
undefined (reading ‘push’)  
at createPlanet (code.html:57:13)  
at addPlanets (code.html:40:7)  
at code.html:33:3  
at \_.html:10:12

Other than that, there are no other errors, which really puzzles me.  
So I made a new file and tried pushing a mesh into a list–and it worked. No errors whatsoever.  
Basically, I have no clue what’s wrong here. ☹

---

<div class="post-metadata">

**Author:** ![Moldy-Mango](https://talk.code3dgames.com/user_avatar/talk.code3dgames.com/moldy-mango/32/70_2.png) [@Moldy-Mango](https://talk.code3dgames.com/u/Moldy-Mango)\
**Post date:** [September 24, 2023, 12:26am UTC](https://talk.code3dgames.com/t/cannot-add-mesh-to-my-array/641/4 "2023-09-24T00:26:58Z")

</div>

(And here’s my updated code, just in case you need it)

[https://www.code3dgames.com/3de/#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](https://www.code3dgames.com/3de/#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)

---

<div class="post-metadata">

**Author:** ![chris](https://talk.code3dgames.com/user_avatar/talk.code3dgames.com/chris/32/5_2.png) [@chris](https://talk.code3dgames.com/u/chris)\
**Post date:** [September 24, 2023, 4:09am UTC](https://talk.code3dgames.com/t/cannot-add-mesh-to-my-array/641/5 "2023-09-24T04:09:23Z")

</div>

You’ve run into a quirky JavaScript feature. JavaScript needs variables – like `planets` – to be defined before they’re used. Instead of this:

```auto
  var gameOver = false;  
  addPlanets();
  var avatar = addAvatar();
  var planets = [];

```

You need to put the `planets` variable before the call to `addPlanets()`:

```auto
  var gameOver = false;  
  var planets = [];
  addPlanets();
  var avatar = addAvatar();

```

It’s weird because JavaScript thinks the variable is being used as soon as you call the `addPlanets()` function. Even though `planets` _is_ defined above `addPlanets()`. JavaScript can be strange.

-Chris

---

<div class="post-metadata">

**Author:** ![Moldy-Mango](https://talk.code3dgames.com/user_avatar/talk.code3dgames.com/moldy-mango/32/70_2.png) [@Moldy-Mango](https://talk.code3dgames.com/u/Moldy-Mango)\
**Post date:** [September 25, 2023, 12:04am UTC](https://talk.code3dgames.com/t/cannot-add-mesh-to-my-array/641/6 "2023-09-25T00:04:53Z")

</div>

It’s working now! Thanks!