Editing Length (section)

=== Graph theory ===
In an [[unweighted graph]], the length of a [[Cycle (graph theory)|cycle]], [[Path (graph theory)|path]], or [[Walk (graph theory)|walk]] is the number of [[Edge (graph theory)|edge]]s it uses.<ref>{{Cite web|url=https://primes.utm.edu/graph/glossary.html|title=Graph Theory Glossary|last=Caldwell|first=Chris K.|date=1995}}</ref> In a [[weighted graph]], it may instead be the sum of the weights of the edges that it uses.<ref>{{Cite web|url=http://www.mathcs.emory.edu/~cheung/Courses/323/Syllabus/Graph/dijkstra1.html|title=Weighted graphs and path length|last=Cheung|first=Shun Yan}}</ref>

Length is used to define the [[shortest path]], [[girth (graph theory)|girth]] (shortest cycle length), and [[longest path]] between two [[Vertex (graph theory)|vertices]] in a graph.