Setting the visible layers from a map service

You can control the visibility of individual layers within a dynamic map service layer using the setVisibleLayers() method. This only applies to dynamic map service layers, not tiled map service layers. This method takes an array of integers corresponding to the data layers in the map service. This array is zero-based so the first layer in the map service occupies position 0. In the Demographics map service illustrated in the following screenshot, Demographics/ESRI_Census_USA (0) occupies index 0:

Therefore, in the event that we'd like to display only the Census Block Points and Census Block Groups from this service we could use setVisibleLayers() as seen in the code example as follows:

var dynamicMapServiceLayer = new ArcGISDynamicMapServiceLayer("http://sampleserver1.arcgisonline.com
   /ArcGIS/rest/services/Demographics/ESRI_Census_USA/MapServer"); 
dynamicMapServiceLayer.setVisibleLayers([0,1]); 
map.addLayer(dynamicMapServiceLayer);