VertexWeightedGraphQ
VertexWeightedGraphQ[g] yields True if the graph g is a vertex-weighted graph, and False otherwise.
Examples
VertexWeightedGraphQ[Graph[{1 -> 2}, VertexWeight -> {1 -> 5}]]VertexWeightedGraphQ[Graph[{a -> b, b -> c}]]Please visit the official Wolfram Language Reference for more details.