var image = new ol.style.Circle({
  radius: 5,
  fill: null,
  stroke: new ol.style.Stroke({color: 'red', width: 1})
});

var styles = {
  'Point': new ol.style.Style({
    image: image
  }),
  'LineString': new ol.style.Style({
    stroke: new ol.style.Stroke({
      color: 'green',
      width: 1
    })
  }),
  'MultiLineString': new ol.style.Style({
    stroke: new ol.style.Stroke({
      color: 'green',
      width: 1
    })
  }),
  'MultiPoint': new ol.style.Style({
    image: image
  }),
  'MultiPolygon': new ol.style.Style({
    stroke: new ol.style.Stroke({
      color: 'yellow',
      width: 1
    }),
    fill: new ol.style.Fill({
      color: 'rgba(255, 255, 0, 0.1)'
    })
  }),
  'Polygon': new ol.style.Style({
    stroke: new ol.style.Stroke({
      color: 'blue',
      lineDash: [4],
      width: 3
    }),
    fill: new ol.style.Fill({
      color: 'rgba(0, 0, 255, 0.1)'
    })
  }),
  'GeometryCollection': new ol.style.Style({
    stroke: new ol.style.Stroke({
      color: 'magenta',
      width: 2
    }),
    fill: new ol.style.Fill({
      color: 'magenta'
    }),
    image: new ol.style.Circle({
      radius: 10,
      fill: null,
      stroke: new ol.style.Stroke({
        color: 'magenta'
      })
    })
  }),
  'Circle': new ol.style.Style({
    stroke: new ol.style.Stroke({
      color: 'red',
      width: 2
    }),
    fill: new ol.style.Fill({
      color: 'rgba(255,0,0,0.2)'
    })
  })
};

var styleFunction = function(feature) {
  return styles[feature.getGeometry().getType()];
};

var geojsonObject = {
  'type': 'FeatureCollection',
  'crs': {
    'type': 'name',
    'properties': {
      'name': 'EPSG:3857'
    }
  },
  'features': [{
    'type': 'Feature',
    'geometry': {
      'type': 'Point',
      'coordinates': [0, 0]
    }
  }, {
    'type': 'Feature',
    'geometry': {
      'type': 'LineString',
      'coordinates': [[4e6, -2e6], [8e6, 2e6]]
    }
  }, {
    'type': 'Feature',
    'geometry': {
      'type': 'LineString',
      'coordinates': [[4e6, 2e6], [8e6, -2e6]]
    }
  }, {
    'type': 'Feature',
    'geometry': {
      'type': 'Polygon',
      'coordinates': [[[-5e6, -1e6], [-4e6, 1e6], [-3e6, -1e6]]]
    }
  }, {
    'type': 'Feature',
    'geometry': {
      'type': 'MultiLineString',
      'coordinates': [
        [[-1e6, -7.5e5], [-1e6, 7.5e5]],
        [[1e6, -7.5e5], [1e6, 7.5e5]],
        [[-7.5e5, -1e6], [7.5e5, -1e6]],
        [[-7.5e5, 1e6], [7.5e5, 1e6]]
      ]
    }
  }, {
    'type': 'Feature',
    'geometry': {
      'type': 'MultiPolygon',
      'coordinates': [
        [[[-5e6, 6e6], [-5e6, 8e6], [-3e6, 8e6], [-3e6, 6e6]]],
        [[[-2e6, 6e6], [-2e6, 8e6], [0, 8e6], [0, 6e6]]],
        [[[1e6, 6e6], [1e6, 8e6], [3e6, 8e6], [3e6, 6e6]]]
      ]
    }
  }, {
    'type': 'Feature',
    'geometry': {
      'type': 'GeometryCollection',
      'geometries': [{
        'type': 'LineString',
        'coordinates': [[-5e6, -5e6], [0, -5e6]]
      }, {
        'type': 'Point',
        'coordinates': [4e6, -5e6]
      }, {
        'type': 'Polygon',
        'coordinates': [[[1e6, -6e6], [2e6, -4e6], [3e6, -6e6]]]
      }]
    }
  }]
};

var vectorSource = new ol.source.Vector({
  features: (new ol.format.GeoJSON()).readFeatures(geojsonObject)
});

vectorSource.addFeature(new ol.Feature(new ol.geom.Circle([5e6, 7e6], 1e6)));

var vectorLayer = new ol.layer.Vector({
  source: vectorSource,
  style: styleFunction
});

var map = new ol.Map({
  layers: [
    new ol.layer.Tile({
      source: new ol.source.OSM()
    }),
    vectorLayer
  ],
  target: 'map',
  controls: ol.control.defaults({
    attributionOptions: /** @type {olx.control.AttributionOptions} */ ({
      collapsible: false
    })
  }),
  view: new ol.View({
    center: [0, 0],
    zoom: 2
  })
});
