How to convert Turf.js polygon to WKT - geo

Question

I'm using Turf.js to generate circle geometry from point and radius, using the circle functions. Example:
c = turf.circle([0.0, 0.0], 100, {steps:1000, units:'kilometers'})
The returned result is Feature object, and the only way I managed to represent the geometry is by applying c.geometry.coordinates which returns an array.
However, my goal is to generate a WKT or at least a GeoJSON, but I haven't found a way to do so.
Does anyone know how to do it with turf.js or alternatively know of a way to get a WKT representation of a circle with center and radius as inputs?

Answer 1

To get GeoJSON text of the feature, you can do this
var gjs = JSON.stringify(polygon_object);
(Inverse check) To parse the string gjs and convert it back to object (GeoJSON) again
var ojn = JSON.parse(gjs);
Live code:-
const pgon = turf.polygon(
[
[
[50.848677, 4.338074],
[50.833264, 4.344961],
[50.840809, 4.366227],
[50.852455, 4.367945],
[50.858306, 4.346693],
[50.848677, 4.338074]
]
],
{ name: "pgon1" }
);
const coords0 = pgon.geometry.coordinates[0];
// Create WKT of the polygon
var phead = `POLYGON((`;
var ptail = `))`;
var pbody = "";
var cur_xy = "";
coords0.forEach( function(item, index){
//console.log(item, index);
//lonlat.push([...item]); //OK
cur_xy = item[0].toFixed(4) +" "+ item[1].toFixed(4);
pbody += cur_xy + ",";
}, pbody);
console.log("*WKT*", phead+pbody+cur_xy+ptail);
// Create geojson of the polygon
console.log("*GeoJSON*" + JSON.stringify(pgon));
<script src="https://cdnjs.cloudflare.com/ajax/libs/Turf.js/5.1.5/turf.min.js"></script>
<p>TurfJS uses GeoJSON to represent geometric features. Here a polygon feature is created and its geometry / properties are manipulated.<br/><br/>The result is printed on the console.</p>