Openlayers 3.10 can't display features added manually

Question

I'm trying to add features manually to vector layer but with no luck. This is my code:

cords[0] = {
[19.1820888104, 49.6835693017],
[19.1819108957, 49.6850423191],
[19.1846518426, 49.6853635871],
[19.1864287796, 49.6845787109],
[19.1864490975, 49.6839272706],
[19.1853396287, 49.6834588915],
[19.1835425444, 49.6834155484],
[19.182316043, 49.6832563996],
[19.1820888104, 49.6835693017]}

var featurething = new ol.Feature({
    geometry: new ol.geom.LineString(cords[0])
    }); 
var layerV = new ol.layer.Vector({
        source: new ol.source.Vector({
            features: featurething
        }),
        visible: true
    }); 
map.addLayer(layerV);

When I check layerV object in console it looks okay (it has feature with proper geometry) but it's not displaying on map. Any idea what's wrong?

Answer 1

Here a correction (it seems your sample coordinates were not well formatted, made some changes)

You can try it copying and pasting in the browser debugger console at https://openlayers.org/en/v4.6.5/examples/simple.html

// It was not possible to use an object with multiple array,
// so some changed in input coordinates
var cords = [
  [19.1820888104, 49.6835693017],
  [19.1819108957, 49.6850423191],
  [19.1846518426, 49.6853635871],
  [19.1864287796, 49.6845787109],
  [19.1864490975, 49.6839272706],
  [19.1853396287, 49.6834588915],
  [19.1835425444, 49.6834155484],
  [19.182316043, 49.6832563996],
  [19.1820888104, 49.6835693017]
];

// Coordinates can be longitude, latitude (EPSG:4326) but you must
// convert them manually to map projection, spherical mercator (EPSG:3857)
// hence the transform function
var geometry = new ol.geom.LineString(cords).transform('EPSG:4326', 'EPSG:3857');

var featurething = new ol.Feature({
  geometry: geometry
});
// You were using an ol.Feature instead of an array of ol.Feature
var layerV = new ol.layer.Vector({
  source: new ol.source.Vector({
    features: [featurething]
  }),
  visible: true
});
map.addLayer(layerV);
// Add to zoom to prove it works
map.getView().fit(layerV.getSource().getExtent());