Question: I can easily get the data working in my HTML, but when I have to convert it for visualization purposes it is a struggle. 

I get the data as a FirebaseListObservable. In my case there's 3 value-types in each List, but it is only one of them there has to be part of the array. How do I convert a FirebaseListObservable to an array in typescript? 

The reason of converting is to use graphs in my app. 

Typescript getting the data:

```
this.measure= this.db.list('/Users/'+this.username+'/Measure');
enter code here

```

Typescript for chartjs

```
this.data = [12, 24, 91, 23] 

```

The data has to be the data from the firebase

Answer: 
Declare a empty array `data=[];`

then get the data with `.subscribe()`

```
this.db.list('/Users/'+this.username+'/Measure').subscribe(measures => {
    measures.forEach(measure => {
      this.data.push(measure.number);//.number should be your field in firebase
    })
  })

```

this will fetch all list and search through all items and push your desired values to the array.
`FirebaseListObservable` is an observable. That means you will get the list itself (=the array you want) when you **subscribe** to it.

```
this.measure: FirebaseListObservable<Measure[]> = this.db.list('/Users/'+this.username+'/Measure');
this.measure
    .map(measurement => measurement.numbers) // this extracts only numbers field so we have basically array of arrays
    .map(numbersArrays => numbersArrays.reduce((curr, prev) => curr.concat(prev))) // so lets concat all those arrays into a single one
    .subscribe(numbersArray: number[] => {
        console.log(numbersArray);
    });

interface Measure {
    data: Date;
    geolocation: string;
    numbers: number[];
}

```