I was trying different ways to display one country using countries.geojson file, but I unable to display.
I tried like this, but map is not displaying....

var map = new ol.Map({ layers : [ new ol.layer.Tile({ source : new ol.source.OSM() }), vector ], target : document.getElementById('map'), view : new ol.View({ center : [ 0,0 ], zoom : 4 }) }); var vector = new ol.layer.Vector({ source: new ol.source.Vector({ format: new ol.format.GeoJSON(), url: 'https://raw.githubusercontent.com/openlayers/ol3/6838fdd4c94fe80f1a3c98ca92f84cf1454e232a/examples/data/geojson/countries.geojson' }), style: function(feature, res){ if(feature.get("name") == "Germany"){ return new ol.style.Style({ stroke: new ol.style.Stroke({ color: 'red', width: 2 }) }); } } });