Scale Line

Example of a scale line.

<!DOCTYPE html>
    <title>Scale Line</title>
    <link rel="stylesheet" href="" type="text/css">
    <!-- The line below is only needed for old environments like Internet Explorer and Android 4.x -->
    <script src=",Element.prototype.classList,URL"></script>

    <div id="map" class="map"></div>
    <select id="units">
      <option value="degrees">degrees</option>
      <option value="imperial">imperial inch</option>
      <option value="us">us inch</option>
      <option value="nautical">nautical mile</option>
      <option value="metric" selected>metric</option>
      import Map from 'ol/Map.js';
      import View from 'ol/View.js';
      import {defaults as defaultControls, ScaleLine} from 'ol/control.js';
      import TileLayer from 'ol/layer/Tile.js';
      import OSM from 'ol/source/OSM.js';

      var scaleLineControl = new ScaleLine();

      var map = new Map({
        controls: defaultControls().extend([
        layers: [
          new TileLayer({
            source: new OSM()
        target: 'map',
        view: new View({
          center: [0, 0],
          zoom: 2

      var unitsSelect = document.getElementById('units');
      function onChange() {
      unitsSelect.addEventListener('change', onChange);