Info Windows

HTML

<!DOCTYPE html>
<html>
  <head>
    <title>Info Windows</title>
    <script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script>
    <script
      src="https://maps.googleapis.com/maps/api/js?key=AIzaSyBIwzALxUPNbatRBj3Xi1Uhp0fFzwWNBkE&callback=initMap&libraries=&v=weekly"
      defer
    ></script>
    <!-- jsFiddle will insert css and js -->
  </head>
  <body>
    <div id="map"></div>
  </body>
</html>

CSS

/* Always set the map height explicitly to define the size of the div
       * element that contains the map. */
#map {
  height: 100%;
}

/* Optional: Makes the sample page fill the window. */
html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
}

JavaScript

// This example displays a marker at the center of Australia.
// When the user clicks the marker, an info window opens.
function initMap() {
  const uluru = { lat: -25.363, lng: 131.044 };
  const map = new google.maps.Map(document.getElementById("map"), {
    zoom: 4,
    center: uluru,
  });
  const contentString =
    '<div id="content">' +
    '<div id="siteNotice">' +
    "</div>" +
    '<h1 id="firstHeading" class="firstHeading">Uluru</h1>' +
    '<div id="bodyContent">' +
    "<p><b>Uluru</b>, also referred to as <b>Ayers Rock</b>, is a large " +
    "sandstone rock formation in the southern part of the " +
    "Northern Territory, central Australia. It lies 335&#160;km (208&#160;mi) " +
    "south west of the nearest large town, Alice Springs; 450&#160;km " +
    "(280&#160;mi) by road. Kata Tjuta and Uluru are the two major " +
    "features of the Uluru - Kata Tjuta National Park. Uluru is " +
    "sacred to the Pitjantjatjara and Yankunytjatjara, the " +
    "Aboriginal people of the area. It has many springs, waterholes, " +
    "rock caves and ancient paintings. Uluru is listed as a World " +
    "Heritage Site.</p>" +
    '<p>Attribution: Uluru, <a href="https://en.wikipedia.org/w/index.php?title=Uluru&oldid=297882194">' +
    "https://en.wikipedia.org/w/index.php?title=Uluru</a> " +
    "(last visited June 22, 2009).</p>" +
    "</div>" +
    "</div>";
  const infowindow = new google.maps.InfoWindow({
    content: contentString,
  });
  const infowindow2 = new google.maps.InfoWindow({
    content: contentString,
  });
  const marker = new google.maps.Marker({
    position: uluru,
    map,
    title: "Uluru (Ayers Rock)",
  });
  const marker2 = new google.maps.Marker({
    position: { lat: -20.363, lng: 130.044 },
    map,
    title: "Uluru (Ayers Rock)",
  });
    infowindow.open(map, marker);
    infowindow2.open(map, marker2);
}