test.html


<!DOCTYPE html>
<html>
  <head>
    
  </head>
  <body>
    <button onclick="getGeolocation()">
      Get my coordinates!
    </button>
    <div id="demo"></div>

    <script>
      const demo = document.getElementById('demo');
      function error(err) {
          demo.innerHTML = `Failed to locate. Error: ${err.message}`;
      }

      function success(pos) {
          demo.innerHTML = 'Located.';
          alert(`${pos.coords.latitude}, ${pos.coords.longitude}`);
      }

      function getGeolocation() {
          if (navigator.geolocation) {
              demo.innerHTML = 'Locating…';
              navigator.geolocation.getCurrentPosition(success, error);
          } else { 
              demo.innerHTML = 'Geolocation is not supported by this browser.';
          }
      }
   </script>
   
  </body>
</html>


<script>
/*
var options = {
  enableHighAccuracy: true,
  timeout: 5000,
  maximumAge: 0
};

function success(pos) {
  var crd = pos.coords;

  console.log('Your current position is:');
  console.log(`Latitude : ${crd.latitude}`);
  console.log(`Longitude: ${crd.longitude}`);
  console.log(`More or less ${crd.accuracy} meters.`);
}

function error(err) {
  console.warn(`ERROR(${err.code}): ${err.message}`);
}

navigator.geolocation.getCurrentPosition(success, error, options);


//https://stackoverflow.com/questions/10077606/check-if-geolocation-was-allowed-and-get-lat-lon
function getCoords() {
  return new Promise((resolve, reject) =>
    navigator.permissions ?

      // Permission API is implemented
      navigator.permissions.query({
        name: 'geolocation'
      }).then(permission =>
        // is geolocation granted?
        permission.state === "granted"
          ? navigator.geolocation.getCurrentPosition(pos => resolve(pos.coords)) 
          : resolve(null)
      ) :

    // Permission API was not implemented
    reject(new Error("Permission API is not supported"))
  )
}

getCoords().then(coords => alert(coords))
*/
</script>