JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyA-OlPHUh2W7LUZXVjQjjxQ8fdCWdJISmc"></script>
<div id="map" ></div>

CSS

#map{width:500px; height:500px; float:left;}

JavaScript

var map;
var uluru = {lat:-17,lng: -47};
var infowindow = null;
function initialize(){
		var map = new google.maps.Map(document.getElementById('map'), {
					zoom: 10,
					center: uluru,
					mapTypeId: google.maps.MapTypeId.SATELLITE
		});
    
    var infowindow = new google.maps.InfoWindow({
					content: '<p><a href="#" id="zoom_mais"><b>+++++</b> </a> | <a href="#" id="zoom_menos"><b>-------</b></a></p>'
		});
    
    var marker = new google.maps.Marker({
					position: uluru,
					draggable: true,
					map: map,
		});
    
    marker.addListener('click', function() {
					infowindow.open(map, marker);
		});
    
		google.maps.event.addListener(marker, 'dragstart', function() {
					if (infowindow) {
						infowindow.close();
						//infoWindow = null;
					}
					infowindow;
					console.log('dragstart')
		});
    
    
    google.maps.event.addListener(marker, 'dragend', function () {
					map.setCenter(this.getPosition()); // Set map center to marker position
          infowindow.open(map, marker);

		});	
    
    //ZOOM
				google.maps.event.addListener(infowindow, 'domready', function() {
					document.getElementById('zoom_mais').addEventListener('click', function(e) {
						map.setZoom(map.getZoom() + 1);
						console.log(map.getZoom());
					});
					document.getElementById('zoom_menos').addEventListener('click', function(e) {
						map.setZoom(map.getZoom() - 1);
						console.log(map.getZoom());			
					});
				});

}

initialize();