what is a better way to get all graphicsLayer (not feature layer) only?

[Alexwang]

which one is better? or are there any better ways of doing this? thanks,

if ( map.getLayer(map.graphicsLayerIds).type != "Feature Layer")

or

if ( !map.getLayer(map.graphicsLayerIds).hasOwnProperty("type"))

or

.....

[XiaodongWang · Accepted solution]

Try it:

if ( map.getLayer(map.graphicsLayerIds).declaredClass === "esri.layers.GraphicsLayer")