Leaflet FeatureCollection: LatLong is undefined - leaflet

Question

I am looking to create a GeoJson instance from a database request with PHP.
I am using this package to create the instance:
http://jmikola.github.io/geojson/api/class-GeoJson.Feature.FeatureCollection.html
I have created the FeatureCollection but I am getting an error
"Error: Invalid LatLng object: (undefined, undefined)"
even though my coordinates are floats.
However, the coordinates are not coming through an array [,], but as a Javascript objects {,} that are inside an array and maybe this is the problem?
Secondly, I think I am having trouble setting the CRS. I can successfully create the GeoJSON in QGIS and it appears at the top of the FeatureCollection but with this package in PHP it appears towards the end.
My feature collection looks like this:
{
"type": "FeatureCollection",
"features": [
{
"type": "Feature",
"geometry": {
"type": "MultiPoint",
"coordinates": [
{...},
{...}
]
},
"properties": [
{...},
{...}
],
"id": {
"type": "name",
"properties": {
"name": "urn:ogc:def:crs:OGC:1.3:CRS84"
}
}
}
]
}
I hope someone can help because I have been trawling through forums for hours!
Cheers

Answer 1

Yes, the coordinates and properties must be arrays, and not objects. Therefore, you can transform those before trying to create your geoJSON, like this:
//loop through all your features
featureCollection.features.forEach(function(feature) {
// first the coordinates in the geometry property
feature.geometry.coordinates.forEach(function(coord, index) {
feature.geometry.coordinates[index] = [coord.lat, coord.lng];
});
// then those in the properties
feature.properties.forEach(function(prop, index) {
feature.properties[index] = [prop.lat, prop.lng];
});
});