How to set dashed line on Leaflet?

Question

Line style in leaflet always are solid ,I want the line to be -1)Dashed line style -2)Train line style

  var L2 = new L.geoJson(L2, {
  style: function(feature) {
    return {
      color: 'black',
      weight: 7
    };
  },
  onEachFeature: function(feature, layer) {
    layer.on({
      'mousemove': function(e) {
        e.target.setStyle({
          weight: 7,
          color: 'red'
        });

      },
      'mouseout': function(e) {
        L2.resetStyle(e.target);
      },
      'click': function(e) {
        mymap.fitBounds(e.target.getBounds());
        L2.bindPopup("<b>" + feature.properties.Nom);
      }
    });
  }
}).addTo(mymap);

Here is my code result

Answer 1

This is an example of a polyline formatted as train track / railway road. Three polylines are drawn on top of each other using dashArray.

plTrainPost[0] = L.polyline(latlonPost, {color: 'black', weight: '5'});
plTrainPost[1] = L.polyline(latlonPost, {color: 'black', weight: '3',  dashArray: '20, 20', dashOffset: '0'});
plTrainPost[2] = L.polyline(latlonPost, {color: 'white', weight: '3', dashArray: '20, 20', dashOffset: '20'});
var CPrePostLayer = L.layerGroup(plTrainPost[0], plTrainPost[1], plTrainPost[2]]);
var overlayMaps = {"An-/Rückfahrt": CPrePostLayer};
L.control.layers(baseMaps, overlayMaps).addTo(mymap);

If you want the track to appear in black only, you will not need plTrainPost[1]. Otherwise select the color of that polyline.

Answer 2

Have you noticed the dashArray option for your vector layers?

Forked Plunker: http://plnkr.co/edit/KyHOkjytDJf1QjCO0Nyh?p=preview

As for the "Train line style", that would depend on what you mean, but if it involves more than 1 color, you would probably need some workaround (duplicate your line…)