VertexOutDegree
VertexOutDegree[g] gives the list of vertex out-degrees for all vertices in the graph g.
VertexOutDegree[g, v] gives the vertex out-degree for the vertex v.
VertexOutDegree[{v -> w, ...}, ...] uses rules v->w to specify the graph g.
Examples
VertexOutDegree[Graph[{1 -> 2, 2 -> 3, 1 -> 3}]]
(* {2, 1, 0} *)VertexOutDegree[Graph[{1 -> 2, 2 -> 3}], 1]
(* 1 *)Please visit the official Wolfram Language Reference for more details.