JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://openlayers.org/en/v3.0.0/css/ol.css">
<script src="http://openlayers.org/en/v3.0.0/build/ol.js"></script>
 <div id="map" class="map"></div>

CSS

.map {
    height: 100%;
    width: 100%;
}

JavaScript

// init map
        var map = new ol.Map({
            target: 'map',
            layers: [
                new ol.layer.Tile({
                    source: new ol.source.MapQuest({layer: 'osm'}) // Street mapa -> osm
                })
            ],
            // pos on map
            view: new ol.View({
                center: ol.proj.transform([17.813988, 43.342019], 'EPSG:4326', 'EPSG:3857'), 
                zoom: 3
            })
        });
    
    
    
    
        var vectorSource = new ol.source.Vector({
            //create empty vector
        });
    
        var markers = [];
    
        function AddMarkers() {
            //create a bunch of icons and add to source vector
            for (var i=0;i<50;i++){
                var x= Math.random()*360-180;
                var y= Math.random()*180-90;
    
                var iconFeature = new ol.Feature({
                    geometry: new ol.geom.Point(ol.proj.transform([x,y], 'EPSG:4326',   'EPSG:3857')),
                    name: 'Marker ' + i
                });
                markers[i]= [x,y];
                vectorSource.addFeature(iconFeature);
            }
    
            //create the style
            var iconStyle = new ol.style.Style({
                image: new ol.style.Icon(/** @type {olx.style.IconOptions} */ ({
                    anchor: [0.5, 46],
                    anchorXUnits: 'fraction',
                    anchorYUnits: 'pixels',
                    opacity: 0.75,
                    src: 'http://upload.wikimedia.org/wikipedia/commons/a/ab/Warning_icon.png'
                }))
            });
    
    
    
            //add the feature vector to the layer vector, and apply a style to whole layer
            var vectorLayer = new ol.layer.Vector({
                source: vectorSource,
                style: iconStyle
            });
            return vectorLayer;
        }
    
        var layerMarkers = AddMarkers();

        map.addLayer(layerMarkers);
       ...