title: Google Maps v3: check if point exists in polygon
body: <p>I am looking to find a way of checking if a point exists inside a polygon in Google Maps v3 (JavaScript). I've searched everywhere and the only solutions I have found so far have been to do with getting the bounds of the polygon, but the code shown seems to just create a rectangle and keeps expanding its surface area to include all relevant points. </p>
  
  <p>By the way, the reason I can't just use a big square i.e. getting a polygons bounds, is that I have bordering polygons on the map and they can not expand into each other's territory.</p>
  
  <p>EDIT
  Following on from the reply below, I have tried implementing the example code using one of my existing polygons but it is just saying that it is not defined and I can't figure out why.</p>
  
  <p>Here is my declaration: </p>
  
  <pre class="lang-js prettyprint-override"><code>myCoordinates = [
      new google.maps.LatLng(0.457301,-0.597382),
      new google.maps.LatLng(0.475153,-0.569916),
      new google.maps.LatLng(0.494379,-0.563049),
      new google.maps.LatLng(0.506738,-0.553436),
      new google.maps.LatLng(0.520470,-0.541077),
      new google.maps.LatLng(0.531456,-0.536957),
      new google.maps.LatLng(0.556174,-0.552063),
      new google.maps.LatLng(0.536949,-0.596008),
      new google.maps.LatLng(0.503991,-0.612488),
      new google.maps.LatLng(0.473780,-0.612488) ];
  
  polyOptions = { 
      path: myCoordinates,
      strokeColor: "#FF0000",
      strokeOpacity: 0.8,
      strokeWeight: 2,
      fillColor: "#0000FF",
      fillOpacity: 0.6 };
  
  var rightShoulderFront = new google.maps.Polygon(polyOptions);
  rightShoulderFront.setMap(map);
  </code></pre>
  
  <p>and here is where I am checking for the point:</p>
  
  <pre class="lang-js prettyprint-override"><code>var coordinate = selectedmarker.getPosition();
  var isWithinPolygon = rightShoulderFront.containsLatLng(coordinate);
  console.log(isWithinPolygon);
  </code></pre>
  
  <p>But it keeps coming up with the error: Uncaught ReferenceError: rightShoulderFront is not defined</p>