indexOf
Determines the index of a given layer in the collection.
Return
The index of the layer in the collection, or -1 if the layer does not exist in the collection.
Parameters
layer
The layer to find the index of.
Determines the index of a given layer in the collection.
The index of the layer in the collection, or -1 if the layer does not exist in the collection.
The layer to find the index of.