# Envelope

A geometry that represents a rectangular shape. An Envelope is an axis-aligned box described by the coordinates of the lower left corner and the coordinates of the upper right corner. They are commonly used to represent the spatial extent covered by layers or other geometries, or to define an area of interest. They can be used as the geometry for a graphic and as an input for many spatial operations. Although they both represent a geographic area, an Envelope is distinct from a Polygon, and they cannot always be used interchangeably.

New instances of Envelope are defined by specifying a minimum and maximum x-coordinate and minimum and maximum y-coordinate, and a SpatialReference. Optionally, a minimum and maximum z-value can be specified to define the depth of the envelope.

## See also

## Constructors

Creates an envelope from any two points. The spatial reference of the points must be the same. The spatial reference of the result envelope comes from the points. If the values for min parameters are bigger than max parameters then they are re-ordered. The resulting envelope always has min less than or equal to max.

Creates an Envelope based on the x, y, z and m values with a spatial reference.

## Types

## Functions

Check if two geometries are equal to within some tolerance. This function performs a lightweight comparison of two geometries, such as might be useful when writing test code. It uses the tolerance to compare each of x, y, and any other values the geometries possess (such as z or m) independently in the manner: abs(value1 - value2) <= tolerance. Returns true if the difference of each is within the tolerance and all other properties of the geometries are exactly equal (spatial reference, vertex count, etc.). A single tolerance is used even if the units for the horizontal coordinates and other values differ, e.g horizontal coordinates in degrees and vertical coordinates in meters. This function does not respect modular arithmetic of spatial references which wrap around, so longitudes of -180 and +180 degrees are considered to differ by 360 degrees. Returns false if an error occurs. For topological equality, use relational operators instead of this function. See GeometryEngine.equals(Geometry, Geometry).

## Properties

The number of dimensions for the geometry. Returns GeometryDimension.Unknown if an error occurs.

True if this geometry contains curve segments; false otherwise. The ArcGIS Platform supports polygon and polyline geometries that contain curve segments (where Segment.getIsCurve() is true, sometimes known as true curves or nonlinear segments). Curves may be present in certain types of data - for example Mobile Map Packages (MMPK) or geometry JSON. When connecting to ArcGIS feature services that support curves[ArcGISFeatureServiceInfo.getSupportsTrueCurve()], ArcGIS Maps API retrieves densified versions of curve feature geometries by default.