Typescript push to specific key in array

Question

I am working on Angular2 project using Firebase.

I need to push all query results under the same key in this.guestPush.

I have a multiple select element which contains different user levels. 4, 6, 9.

When one level is selected, the resulting object is saved in the guestPush array, but when another level is selected the following error occurs.

I get this error:

ERROR TypeError: this.guestPush[("filter" + i)].push is not a function

Here is my code :

  guestPush: any[] = new Array;

  level.forEach((lvl, index) => {

    this.db.object(`levelsUsers/${lvl}/users`)
      .subscribe(users => {

        if (this.guestPush['filter_' + i]) {
          this.guestPush['filter_' + i].push(users);
        } else {
          this.guestPush['filter_' + i] = users;
        }

      }, err => console.log(err));

  });

Edit ***

The users object which contains the user or users which match the filter:

Object {-KmSjAaxdCUvrPEQ8InI: Object, $key: "users", $exists: function}
  -KmSjAaxdCUvrPEQ8InI: Object
    admin:"false"
    description:"desc"
    ...
    ...
    verified:false
  __proto__:Object
  exists:function ()
  $key:"users"
  __proto__:Object

And this.guestPush[i] = users; creates an object like this:

[Object]
 0:Object
 -KmSjAaxdCUvrPEQ8InI: Object
    admin:"false"
    description:desc"
    ...
    ...
    verified:false
    __proto__:Object
  $exists:function ()
  $key:"users"
  __proto__:Object
 length:1
 __proto__:Array(0)

So in the next loop I want to add any new user objects next to -KmSjAaxdCUvrPEQ8InI or anything as long as it is added as a value of the 0 key.

Answer 1

Looks like you are getting an array response and you are assigning it to the object :

this.guestPush['filter_' + i] = users;

so this.guestPush['filter_'+ i] is of type array now. If you want to add another users object to it , you are essentially adding another array to existing array. In that case shouldn't you be using concat ?

if (this.guestPush['filter_' + i]) {
    this.guestPush['filter_' + i].concat(users);
} else {
    this.guestPush['filter_' + i] = users;
}

if users is not an array, then it should be

if (this.guestPush['filter_' + i]) {
    this.guestPush['filter_' + i].push(users);
} else {
    this.guestPush['filter_' + i] = [users];
}

Answer 2

I ended up using

 this.guestPush.push({ [i]: { [key]: obj } });