index.ts

/**
 * @license
 * Copyright 2019 Google LLC. All Rights Reserved.
 * SPDX-License-Identifier: Apache-2.0
 */

// [START maps_advanced_markers_zoom]
const mapElement = document.querySelector('gmp-map') as google.maps.MapElement;

async function initMap() {
  // Request needed libraries.
  const { Map } = (await google.maps.importLibrary(
    'maps'
  )) as google.maps.MapsLibrary;
  const { AdvancedMarkerElement } = (await google.maps.importLibrary(
    'marker'
  )) as google.maps.MarkerLibrary;

  const markerOptions = [
    {
      position: { lat: 37.4239163, lng: -122.094 },
      title: 'This marker is visible at zoom level 15 and higher.',
      minZoom: 14,
    },
    {
      position: { lat: 37.4245, lng: -122.096 },
      title: 'This marker is visible at zoom level 16 and higher.',
      minZoom: 15,
    },
    {
      position: { lat: 37.4249, lng: -122.095 },
      title: 'This marker is visible at zoom level 17 and higher.',
      minZoom: 16,
    },
    {
      position: { lat: 37.425, lng: -122.0955 },
      title: 'This marker is visible at zoom level 18 and higher.',
      minZoom: 17,
    },
  ];

  const markers: google.maps.marker.AdvancedMarkerElement[] = [];
  for (const { position, title } of markerOptions) {
    const marker = new AdvancedMarkerElement({ position, title });
    mapElement.append(marker);
    markers.push(marker);
  }

  // [START maps_advanced_markers_zoom_listener]
  mapElement.innerMap.addListener('zoom_changed', () => {
    let zoom = mapElement.innerMap.getZoom();
    for (let i = 0; i < markers.length; i++) {
      const { position, minZoom } = markerOptions[i];
      markers[i].position = zoom! > minZoom ? position : null;
    }
  });
  // [END maps_advanced_markers_zoom_listener]
}

initMap();
// [END maps_advanced_markers_zoom]