Angular5 Autocomplete search from array

Question

I am building a filter for finding city`s. I have an array with citynames. (this.place = [Londen, Amsterdam, Rome, Paris])

I have an inputfield when a user types a letter in the inputfield I want to search through the array and give him a list of suggestions.

I tried this but it does not work:

Html:
    <input #inputValue (keyup)="filterValues($event)" />
            <div *ngIf='placesFound'>
            <span *ngFor="let place of placesFound">
              {{place}}
            </span>
        </div>

TS file:

  filterValues(event) {


    let key = event.key
   this.placesFound = this.places.filter(function(event) {
      return this.places.indexOf(key) > -1
    })

  }

this does not work does someone has any suggestions?

thx!