# @turf/dissolve ## dissolve Dissolves a FeatureCollection of [polygon][1] features, filtered by an optional property name:value. Note that [mulitpolygon][2] features within the collection are not supported **Parameters** - `featureCollection` **[FeatureCollection][3]<[Polygon][4]>** input feature collection to be dissolved - `options` **[Object][5]** Optional parameters (optional, default `{}`) - `options.propertyName` **[string][6]?** features with equals 'propertyName' in `properties` will be merged **Examples** ```javascript var features = turf.featureCollection([ turf.polygon( [ [ [0, 0], [0, 1], [1, 1], [1, 0], [0, 0], ], ], { combine: "yes" } ), turf.polygon( [ [ [0, -1], [0, 0], [1, 0], [1, -1], [0, -1], ], ], { combine: "yes" } ), turf.polygon( [ [ [1, -1], [1, 0], [2, 0], [2, -1], [1, -1], ], ], { combine: "no" } ), ]); var dissolved = turf.dissolve(features, { propertyName: "combine" }); //addToMap var addToMap = [features, dissolved]; ``` Returns **[FeatureCollection][3]<[Polygon][4]>** a FeatureCollection containing the dissolved polygons [1]: polygon [2]: mulitpolygon [3]: https://tools.ietf.org/html/rfc7946#section-3.3 [4]: https://tools.ietf.org/html/rfc7946#section-3.1.6 [5]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object [6]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String --- This module is part of the [Turfjs project](http://turfjs.org/), an open source module collection dedicated to geographic algorithms. It is maintained in the [Turfjs/turf](https://github.com/Turfjs/turf) repository, where you can create PRs and issues. ### Installation Install this module individually: ```sh $ npm install @turf/dissolve ``` Or install the Turf module that includes it as a function: ```sh $ npm install @turf/turf ```