This version is out of date, covering development from v9.0.0 to v9.3.0. It is maintained here only for inbound reference links from elsewhere. It is no longer actively updated.

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 Function   [other Function type actions]

 List   [operators of similar scope]

 Data manipulation   [other Data manipulation operators]




This calculates the intersection of two List or Sets. The .intersect() test is generally intended for use with Set-type data but will work with Lists, though the result is always a Set.

$MySet = $MySetA.intersect($MySetB); 

$MySet = $MyList1.intersect($MyList2); 

The result is a Set of all items in both $MySetA and $MySetB, or in the second example in both $MyList1 and $MyList2. As the result is always a set, any source list items are de-duped in the output.


No special code is needed to find items in one set but not the other:

$MySetC = $MySetA - $MySetB; gives items only in $MySetA

$MySetC = $MySetB - $MySetA; gives items only in $MySetB

Use with Lists

Subtracting a Set from a List results in only one instance of each Set item being removed. Subtracting a List from a List each instance of a value in the second list is removed so multiple source List entries may be removed.