@turf/invariant

getCoord

Unwrap a coordinate from a Point Feature, Geometry or a single coordinate.

Parameters

• coord (Array<number> | Geometry<Point> | Feature<Point>) GeoJSON Point or an Array of numbers

Examples

var pt = turf.point([10, 10]);

var coord = turf.getCoord(pt);
//= [10, 10]

Returns Array<number> coordinates

getCoords

Unwrap coordinates from a Feature, Geometry Object or an Array

Parameters

• coords (Array<any> | Geometry | Feature) Feature, Geometry Object or an Array

Examples

var poly = turf.polygon([[[119.32, -8.7], [119.55, -8.69], [119.51, -8.54], [119.32, -8.7]]]);

var coords = turf.getCoords(poly);
//= [[[119.32, -8.7], [119.55, -8.69], [119.51, -8.54], [119.32, -8.7]]]

Returns Array<any> coordinates

containsNumber

Checks if coordinates contains a number

Parameters

• coordinates Array<any> GeoJSON Coordinates

Returns boolean true if Array contains a number

geojsonType

Enforce expectations about types of GeoJSON objects for Turf.

Parameters

• value GeoJSON any GeoJSON object
• type string expected GeoJSON type
• name string name of calling function

• Throws Error if value is not the expected type.

featureOf

Enforce expectations about types of Feature inputs for Turf. Internally this uses geojsonType to judge geometry types.

Parameters

• feature Feature a feature with an expected geometry type
• type string expected GeoJSON type
• name string name of calling function

• Throws Error error if value is not the expected type.

collectionOf

Enforce expectations about types of FeatureCollection inputs for Turf. Internally this uses geojsonType to judge geometry types.

Parameters

• featureCollection FeatureCollection a FeatureCollection for which features will be judged
• type string expected GeoJSON type
• name string name of calling function

• Throws Error if value is not the expected type.

getGeom

Get Geometry from Feature or Geometry Object

Parameters

• geojson (Feature | Geometry) GeoJSON Feature or Geometry Object

Examples

var point = {
  "type": "Feature",
  "properties": {},
  "geometry": {
    "type": "Point",
    "coordinates": [110, 40]
  }
}
var geom = turf.getGeom(point)
//={"type": "Point", "coordinates": [110, 40]}

• Throws Error if geojson is not a Feature or Geometry Object

Returns (Geometry | null) GeoJSON Geometry Object

getType

Get GeoJSON object's type, Geometry type is prioritize.

Parameters

• geojson GeoJSON GeoJSON object
• _name string?
• name string name of the variable to display in error message (unused) (optional, default "geojson")

Examples

var point = {
  "type": "Feature",
  "properties": {},
  "geometry": {
    "type": "Point",
    "coordinates": [110, 40]
  }
}
var geom = turf.getType(point)
//="Point"

Returns string GeoJSON type

This module is part of the Turfjs project, an open source module collection dedicated to geographic algorithms. It is maintained in the Turfjs/turf repository, where you can create PRs and issues.

Installation

Install this single module individually:

$ npm install @turf/invariant

Or install the all-encompassing @turf/turf module that includes all modules as functions:

$ npm install @turf/turf