Function count() calculates the number of rows of a data column, namely the column length. Only one row from the data stream will be kept after this function is called, and all the rest rows will be abandoned.

Arguments：

• Any Value <any>

Returns：

• Column length <number>

ATTR

Example: deduplicate the elements in an array, count the number of the elements after deduplication

uncollect [1,2,4,5,2,1,3] as a
with distinct(a) as b
return count(b)

Node

Example: find @device nodes, count the number of them

find().nodes({@device}) as n
return count(n)

Edge

Example: find @view edges, count the number of it

find().edges({@view}) as e
return count(e)

Path

Example: find the shortest paths from Card CA001 to CA002 within 5 steps, count the number of the paths

n({_id == "CA001"}).e()[*:5].n({_id == "CA002"}) as p
return count(p)