Function

intersection( array1, array2 )

Returns only those elements that appear in all of the given arrays.

Parameters

Keyword	Type	Description
array1	Any Type Array	Array to intersect.
array2	Any Type Array	Array to intersect.

Returns

Any Type Array, matching the type of the inputs

Examples

Find the values that are common in two integer arrays

intersection({1, 2, 3, 4}, {3, 4, 5, 6}) returns an array with 3, 4

Find the values that are common in two text arrays

Values are matched case sensitively:

intersection({"a", "b", "A"}, {"a", "c"}) returns an array with a

To match items case insensitively, use the lower() function on both inputs.

A value is returned for each match:

intersection({"a", "b", "a"}, {"a"}) returns an array with a, a

Types of the arrays must match

intersection({"a"}, {1}) returns the following error message: Invalid types, can only act on data of the same type.

Use either the conversion functions or the cast() function to convert to the appropriate type.

Empty or null arrays

When one of the arrays is empty, or no common values are found, an empty array of the same type as the inputs is returned:

intersection({1}, tointeger({})) returns an empty integer array.

intersection({"a"}, {"b"}) returns an empty text array.

Null values in the array are matched and returned:

intersection({1, null, 3}, {1, null, 4}) returns an array with 1, <null>

Compare more than two arrays

An unlimited number of arrays can be compared, and the values common to all of them are returned:

intersection({1, 2}, {2, 3}, {2, 4}) returns an array with 2

Scalar inputs

Scalar inputs are cast to arrays:

intersection(1, 1) returns an array with 1

Feature compatibility

The table below lists this function's compatibility with various features in Appian.

Feature	Compatibility	Note
Portals	Compatible
Offline Mobile	Compatible
Sync-Time Custom Record Fields	Compatible	Can be used to create a custom record field that only evaluates at sync time.
Real-Time Custom Record Fields	Incompatible
Process Reports	Compatible
Process Events	Compatible