How to put multiple markers on the map?

Question

Google Maps

There are several elements on the page with different coordinates on the map:

<p id="address">51.481609, -0.018618</p>
 <p id="address">54.481609, -0.018618</p>
 <p id="address">58.481609, -0.018618</p>

How can everyone get all these coordinates and automatically put them on the map, like markers?

var element = document.getElementById('address');
var coordinatesAsText = element.innerText || element.textContent;
var coordinates = coordinatesAsText.split(',');

console.log(coordinates);

    var locations = [
      ['Bondi Beach', coordinates[0],coordinates[1], 4],
      ['Coogee Beach', -33.923036, 151.259052, 5],
      ['Cronulla Beach', -34.028249, 151.157507, 3],
      ['Manly Beach', -33.80010128657071, 151.28747820854187, 2],
      ['Maroubra Beach', -33.950198, 151.259302, 1]
    ];

    var map = new google.maps.Map(document.getElementById('map'), {
      zoom: 10,
      center: new google.maps.LatLng(-33.92, 151.25),
      mapTypeId: google.maps.MapTypeId.ROADMAP
    });

    var infowindow = new google.maps.InfoWindow();

    var marker, i;

    for (i = 0; i < locations.length; i++) {  
      marker = new google.maps.Marker({
        position: new google.maps.LatLng(locations[i][1], locations[i][2]),
        map: map
      });

      google.maps.event.addListener(marker, 'click', (function(marker, i) {
        return function() {
          infowindow.setContent(locations[i][0]);
          infowindow.open(map, marker);
        }
      })(marker, i));
    }

So far, only the first marker is triggered...