Y must be a scalar or vector. X must be a scalar or vector. A scalar X or Y is treated as a one-element vector. R is a vector composed of items occurring in both X and Y in the order of occurrence in X. If an item is repeated in X and also occurs in Y, the item is also repeated in R.
Items in X and Y are considered the same if X≡Y returns 1 for those items.
⎕CT and ⎕DCT are implicit arguments of Intersection.
'ABRA'∩'CAR' ARA 1 'PLUS' 2 ∩ ⍳5 1 2
For performance information, see Search Functions and Hash Tables.