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.

Examples

      'ABRA'∩'CAR'
ARA
 
      1 'PLUS' 2 ∩ ⍳5
1 2

For performance information, see Search Functions and Hash Tables.