JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://google-developers.appspot.com/maps/documentation/javascript/examples/default.css">
<script src="http://maps.google.com/maps/api/js?sensor=false&amp;.js"></script>
<div id="map_canvas"></div>

JavaScript

var lastIndex = 0,
    chicago = new google.maps.LatLng(41.879535, -87.624333),
    mapOptions = {
        zoom: 7,
        center: chicago,
        mapTypeId: google.maps.MapTypeId.ROADMAP
    },

    map = new google.maps.Map(document.getElementById('map_canvas'), mapOptions),
    addCircle = function(ev){
        return new google.maps.Marker({ 
            position: ev.latLng, 
            map: map, 
            zIndex: -99,
            icon: { path: google.maps.SymbolPath.CIRCLE, strokeWeight: 10 }
        });
    },
    addIcon = function(ev){
        var icon = new google.maps.MarkerImage(
            "http://www.mapsmarker.com/wp-content/plugins/leaflet-maps-marker/leaflet-dist/images/marker.png", 
            new google.maps.Size(32, 38)
        );        
        return new google.maps.Marker({ 
            position: ev.latLng, 
            map: map,
            zIndex: 10,
            icon: icon
        });
    };

google.maps.event.addListener(map, 'click', addCircle);


addIcon({latLng:chicago});
addCircle({latLng:new google.maps.LatLng(41.99, -87.625)});