How Can I Use String of Coordinates Within a Mapbox Feature?

Question

I am trying to fetch a comma separated list of coordinates from a database and then show them on a Mapbox GL JS map. By using the following FeatureCollection, I am able to show a Line between coordinates:

const route = {
 'type': 'FeatureCollection',
 'features': [
 {
 'type': 'Feature',
 'geometry': {
 'type': 'LineString',
 'coordinates': [
 [0.05505231549481921,50.795082814869524], [0.054870226332090315,50.79614745729873]
 ]
 }
 }
 ]
 };

This simply draws a line between the two coordinates shown. However using a PHP script to fetch from a MySQL database a string of coordinates, I cannot get the line to show.

<?php
 $array["routeCoords"] = $pointArray; // [0.05505231549481921,50.795082814869524], [0.054870226332090315,50.79614745729873]
 return json_encode($array);

The problem I am facing is that the Mapbox FeatureCollection doesn't recognise the coordinates in the same way as if they were printed within the block itself.

URL of Output:

{"routeCoords":"[0.05505231549481921,50.795082814869524],[0.054870226332090315,50.79614745729873]"}

Jquery code to handle and display the coordinates:

const payload = await fetch(URL); //Url returns JSON data above.
const data = await payload.json();
let coords = [];
$.each(data.routeCoords, function(index, value){
 coords.push(value);
});
coords = JSON.stringify(coords);
const route = {
 'type': 'FeatureCollection',
 'features': [
 {
 'type': 'Feature',
 'geometry': {
 'type': 'LineString',
 'coordinates': [
 coords
 ]
 }
 }
 ]
};

Just getting started but the core of my product will store the LineString coordinates in a database and return them depending on a route, so it is dynamic. There will be other (non geographical) data returned in the same JSON payload so the above is simply cut down.

Hopefully an obvious mistake.

• C3roe: coords = JSON.stringify(coords) - why? In the first code, you passed an array of arrays for coordinates - now you are passing a string value.
• trainmania100: Problem i'm facing is I'm getting an error in console: coord must be GeoJSON Point or an Array of numbers when I pass an array to the coordinates. For example now I have an array and each of the [Long, Lat] formatted Coordinates as individual values in the array, and trying to use that array variable in the Feature code throws that error, despite it being an array of Lon/Lat coords.
• trainmania100: Recon I should probably create the whole Feature as JSON on the server side rather than just the coordinates and see how that goes...