// Load the Map and MapView modules
require(["esri/Map", "esri/views/MapView", "dojo/domReady!"], function(Map, MapView) {
  // Create a Map instance
  var myMap = new Map({
    basemap: 'streets'
  });
  // Create a MapView instance (for 2D viewing) and reference the map instance
  var view = new MapView({
    map: myMap
  });
});

Property Overview

Property Details

allLayersCollection<Layer>readonly

A flat collection of all the layers in the map. This collection contains basemap layers, operational layers and ground layers. Group Layers and their children layers are also part of this collection. Reference layers in the basemap will always be included at the end of the collection.

Layers should not be added directly to this collection. They must only be added via the layers, basemap or ground properties.

Example:

// Find a layer with title "US Counties"
var foundLayer = map.allLayers.find(function(layer) {
 return layer.title === "US Counties";
});

// Create a filtered collection of the non-group layers
var nonGroupLayers = map.allLayers.filter(function(layer) {
 return !foundLayer.layers;
});

// Listen for any layer being added or removed in the Map
map.allLayers.on("change", function(event) {
 console.log("Layer added: ", event.added);
 console.log("Layer removed: ", event.removed);
 console.log("Layer moved: ", event.moved);
});

basemapBasemapautocast

Autocasts from String|Object

Specifies a basemap for the map. The basemap is a set of tile layers that give geographic context to the MapView or SceneView and the other operational layers in the map.

This value can be an instance of Basemap or one of the strings listed in the table below.

Value	Description
streets
satellite
hybrid
topo
gray
dark-gray
oceans
national-geographic
terrain
osm
dark-gray-vector
gray-vector
streets-vector
topo-vector
streets-night-vector
streets-relief-vector
streets-navigation-vector

Example:

// Set the basemap in the constructor
var map = new Map({
  basemap: "streets"
});

// Set the basemap after the map instance is created
map.basemap = "topo";

declaredClassStringreadonly inherited

Since: ArcGIS API for JavaScript 4.7

The name of the class. The declared class name is formatted as esri.folder.className.

groundGroundautocast

Autocasts from String|Object

Specifies the surface properties for the map. This property is only relevant when adding the map to a 3D SceneView. It renders the terrain or topographical variations in the real world on the map's surface with a collection of ElevationLayer.

This value can be an instance of Ground, or one of the following strings:

• world-elevation for a default instance of ground using the Terrain3D Service.
• world-topobathymetry for an instance of ground that combines surface elevation and bathymetry using the TopoBathy3D Service.

The ground may not be set to null or undefined, it is guaranteed to always contain an instance of type Ground. The elevation can be removed from the ground by setting the ground property to a new empty Ground instance or by removing all the ground layers.

See also:

• ElevationLayer
• Ground

Examples:

// Use the world elevation service
var map = new Map({
  basemap: "topo",
  ground: "world-elevation"
});

// Create a map with the world elevation layer overlaid by a custom elevation layer
var worldElevation = ElevationLayer({
  url: "//elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer"
});
var customElevation = ElevationLayer({
  url: "https://my.server.com/arcgis/rest/service/MyElevationService/ImageServer"
});
var map = new Map({
  basemap: "topo",
  ground: new Ground({
   layers: [ worldElevation, customElevation ]
  })
});

layersCollection<Layer>autocast

Autocasts from Layer[]

A collection of operational layers. This property only contains interactive operational layers, such as FeatureLayers, WebTileLayers and GraphicsLayers that may be queried, assigned different renderers, analyzed, etc. It does not include basemaps.

A layer is a collection of one or more features, or graphics, that represent real-world phenomena. Each feature contains a symbol and geographic data that allows it to be rendered on the map as a graphic with spatial context. Features within the layer may also contain data attributes that provide additional information that may be viewed in popup windows and used for rendering the layer.

Layers may be added in the constructor, with the add() or addMany() methods, or directly to the layers collection using add() or addMany().

A layer may only be added to one parent. Adding the same layer to multiple Maps or GroupLayers is not possible. If you attempt to do so, the layer will automatically be removed from its current parent and placed in the new parent.

var layer = new GraphicsLayer();
// The layer belongs to map1
map1.layers.add(layer);
// The layer now belongs to map2
// and implicitly does: map1.layers.remove(layer)
map2.layers.add(layer);

Example:

// Add layers in the constructor of Map using an array
var fl = new FeatureLayer(url);
var gl = new GraphicsLayer();
var map = new Map({
  layers: [fl, gl]
});

// Add layers using add()
map.addMany([fl, gl]);

// Add layers using layers collection
map.layers.addMany([fl, gl]);

Method Overview

Method Details

add(layer, index)

Adds a layer to the layers collection.

Parameters:

layer Layer|Promise<Layer> Layer or a Promise<Layer> to be added to the layers collection.

index Number optional A layer can be added at a specified index in the layers collection. If no index is specified or the index specified is greater than the current number of layers, the layer is automatically appended to the list of layers in the layers collection and the index is normalized.

addMany(layers, index)

Adds a layer or an array of layers to the layers collection.

Parameters:

layers Layer[] Layer(s) to be added to the layers collection.

index Number optional A layer can be added at a specified index in the layers collection. If no index is specified or the index specified is greater than the current number of layers, the layer is automatically appended to the list of layers in the layers collection and the index is normalized.

findLayerById(layerId){Layer}

Returns a layer based on the given layer id.

Parameter:

layerId String The ID assigned to the layer.

Returns:

Type	Description
Layer	Returns the requested layer object.

remove(layer){Layer}

Removes the specified layer from the layers collection.

Parameter:

layer Layer Layer to remove from the layers collection.

Returns:

Type	Description
Layer	Returns the layer removed from the layers collection.

removeAll(){Layer[]}

Removes all layers.

Returns:

Type	Description
Layer[]	Returns the layers removed from the layers collection.

removeMany(layers){Layer[]}

Removes the specified layers.

Parameter:

layers Layer[] Array of layers to remove from the layers collection.

Returns:

Type	Description
Layer[]	Returns the layers removed from the layers collection.

reorder(layer, index){Layer}

Changes the layer order. The first layer added is always the base layer, even if its order is changed.

Parameters:

layer Layer The layer to be moved.

index Number The index location for placing the layer. The bottom-most layer has an index of 0.

Returns:

Type	Description
Layer	Returns the layer that was moved.