Document layerGroup id option

L.layerGroup has a function getLayer that finds layers by ids, but how layers get ids is unexplained

L.layerGroup({ foo: L.tileLayer('') }).getLayer('foo') // no dice

Is there an id option for layers? This needs better explaining around.

[mn113]

Leaflet 1.0 came out but there is still no way to access layers other than with getLayerId(layer) and getLayer(id)…

[skipjack]

Note that there is a fair amount of interest in something like this, you can see that in these two so questions that have garnered a decent number of votes:

• https://stackoverflow.com/questions/13004226/how-to-interact-with-leaflet-marker-layer-from-outside-the-map/37681431?noredirect=1
• https://stackoverflow.com/questions/25683871/assign-id-to-marker-in-leaflet

Disclosure: I do have answers on both of those but in neither are the “leaflet recommended” approach. Would be happy to update my answers if there is one or for someone else to submit a new answer if there is a better/simpler built-in approach.