Showing only selected country from GeoJSON file and hiding remaining unselected country using OpenLayers?

Question

How do I not show any countries except Zambia?

<script type="text/javascript">
         (function() { 
         var inputs  = 'Zambia';//may be any country
         var raster = new ol.layer.Tile({
            source: new ol.source.OSM(),
           projection: 'EPSG:3857'
          });
        var vector = new ol.layer.Vector({
             source: new ol.source.Vector({
             ormat: new ol.format.GeoJSON(),
              url: 'countries.geojson'
            }),
           style: function(feature, res){
               if(feature.get("name") == inputs){
                  return new ol.style.Style({
                  stroke: new ol.style.Stroke({
                   color: 'red',
                   width: 2
                  })
                   });
              } 
          }  
       });
     var map1 = new ol.Map({
        target: 'map',
        layers: [raster, vector],
        view: new ol.View({
     center: ol.proj.transform([27.60315,-13.41099],'EPSG:4326','EPSG:3857'),
     zoom: 6
    })
     });
  })();
</script>

Answer 1

var inputs  = 'Zambia';
                    var raster = new ol.layer.Tile({
                        source: new ol.source.OSM(),
                            projection: 'EPSG:3857'
                    });

                    // vector layer
                    var vector = new ol.layer.Vector({
                         features: [vectorSource],
                        source: new ol.source.Vector({
                            format: new ol.format.GeoJSON(),
                            url: 'countries.geojson'
                        }),
                        style: function(feature, res){
                            if(feature.get("name") != inputs){
                                return new ol.style.Style({
                                     fill: new ol.style.Fill({
                                         color: 'rgb(181, 208, 208)'
                                       })
                                });
                            }
                            if(feature.get("name") == inputs){
                                return new ol.style.Style({
                                    stroke: new ol.style.Stroke({
                                        color: '#319FD3',
                                        width: 2
                                      })
                                });
                            }
                        }
                    });

                    // create first map
                    var map1 = new ol.Map({
                        target: 'map',
                        layers: [ raster,vector],
                        view: new ol.View({
                            center: ol.proj.transform([27.60315,-13.41099], 'EPSG:4326', 'EPSG:3857'),
                            zoom: 6
                        })
                    });