VertexAdd

VertexAdd[g, v] makes a graph by adding the vertex v to the graph g.

• VertexAdd[g, {v1, v2, ...}] adds a collection of vertices to g.
• VertexAdd[{v -> w, ...}, ...] uses rules v -> w to specify the graph g.

Examples

VertexAdd[Graph[{1 -> 2, 2 -> 3}], 4]

VertexAdd[CycleGraph[4], {5, 6}]

Please visit the official Wolfram Language Reference for more details.