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EdgeTags[g]

gives the list of tags for all edges in the graph g.

EdgeTags[g,{u,v}]

gives the list of tags for edges between u and v.

Details
Details and Options Details and Options
Examples  
Basic Examples  
Scope  
Properties & Relations  
Possible Issues  
See Also
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EdgeTags

EdgeTags[g]

gives the list of tags for all edges in the graph g.

EdgeTags[g,{u,v}]

gives the list of tags for edges between u and v.

Details

  • EdgeTags[g] returns the list of edge tags in the order used by the graph g.
  • For a directed graph g, EdgeTags[g,{u,v}] gives tags for edges from u to v.
  • Null is used to indicate the absence of a tag in an edge.
  • When a graph g has no edge with tags, EdgeTags[g] gives an empty list.

Examples

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Basic Examples  (1)

The list of edge tags for an explicitly constructed graph:

Wolfram Language code: Graph[{1Overscript[, a]2, 1Overscript[, b]3, 2Overscript[, c]3}]
Wolfram Language code: EdgeTags[%]

The list of edge tags between 1 and 2:

Wolfram Language code: Graph[{1Overscript[, a]2, 1Overscript[, b]2, 1Overscript[, c]3, 2Overscript[, d]3}]
Wolfram Language code: EdgeTags[%, {1, 2}]

Scope  (5)

EdgeTags works with undirected graphs:

Wolfram Language code: EdgeTags[[image]]

Directed graphs:

Wolfram Language code: EdgeTags[[image]]

Multigraphs:

Wolfram Language code: EdgeTags[[image]]

Mixed graphs:

Wolfram Language code: EdgeTags[[image]]

EdgeTags works with large graphs:

Wolfram Language code: g = IndexEdgeTaggedGraph[GridGraph[{10, 10, 10, 10}]];
Wolfram Language code: Timing[EdgeTags[g]//Short]

Properties & Relations  (4)

EdgeCount can be found using EdgeTags in a tagged graph:

Wolfram Language code: g = EdgeTaggedGraph[{12, 23, 31}]
Wolfram Language code: EdgeCount[g]
Wolfram Language code: Length[EdgeTags[g]]

Tags in EdgeTags are given in the same order their edges are entered for Graph:

Wolfram Language code: g = Graph[{2Overscript[, a]3, 1Overscript[, b]2, 3Overscript[, c]1, 4Overscript[, d]1}]
Wolfram Language code: EdgeTags[%]

EdgeTags gives an empty list for input that is not tagged graphs:

Wolfram Language code: g = GridGraph[{2, 3}]
Wolfram Language code: EdgeTaggedGraphQ[g]
Wolfram Language code: EdgeTags[g]

EdgeTags can be found using EdgeList in IndexEdgeTaggedGraph:

Wolfram Language code: g = IndexEdgeTaggedGraph[WheelGraph[8]]
Wolfram Language code: EdgeTags[g]
Wolfram Language code: Last /@ EdgeList[g]

Possible Issues  (2)

Null is used to indicate the absence of a tag in an edge:

Wolfram Language code: g = Graph[{UndirectedEdge[1, 2, 1], UndirectedEdge[2, 3], UndirectedEdge[3, 1]}]
Wolfram Language code: EdgeTags[g]

EdgeTags gives an empty list for a graph with no edge tags:

Wolfram Language code: g = CompleteGraph[5]
Wolfram Language code: EdgeTags[g]
Wolfram Research (2020), EdgeTags, Wolfram Language function, https://reference.wolfram.com/language/ref/EdgeTags.html.

Text

Wolfram Research (2020), EdgeTags, Wolfram Language function, https://reference.wolfram.com/language/ref/EdgeTags.html.

CMS

Wolfram Language. 2020. "EdgeTags." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/EdgeTags.html.

APA

Wolfram Language. (2020). EdgeTags. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/EdgeTags.html

BibTeX

@misc{reference.wolfram_2026_edgetags, author="Wolfram Research", title="{EdgeTags}", year="2020", howpublished="\url{https://reference.wolfram.com/language/ref/EdgeTags.html}", note=[Accessed: 12-June-2026]}

BibLaTeX

@online{reference.wolfram_2026_edgetags, organization={Wolfram Research}, title={EdgeTags}, year={2020}, url={https://reference.wolfram.com/language/ref/EdgeTags.html}, note=[Accessed: 12-June-2026]}