View this page in the latest version of Appian. union() Function Share Share via LinkedIn Reddit Email Copy Link Print On This Page Function union( array1, array2 ) Returns all unique elements from the given arrays. Parameters Keyword Type Description array1 Any Type Array Array to combine. array2 Any Type Array Array to combine. Returns Any Type Array, matching the type of the inputs Examples Find the superset of values from two integer arrays union({1, 2, 3, 4}, {3, 4, 5, 6}) returns an array with 1, 2, 3, 4, 5, 6 Remove duplicates from an array Remove the duplicates from an array by comparing it with an empty array of the same type: union({1, 2, 3, 4, 1, 2}, tointeger({})) returns an array with 1, 2, 3, 4 This can also be accomplished by comparing an array with itself: union(local!myArray, local!myArray) removes the duplicate elements from local!myArray. Values are matched with case sensitivity union({"a", "b"}, {"a", "B"}) returns an array with a, b, B Array types must match union({"a", "b"}, {1, 2}) returns the following error: Invalid types, can only act on data of the same type. NOTE: Use either the conversion functions or the cast() function to convert to the appropriate type. union({"a", "b"}, tostring({1, 2})) returns an array with a, b, 1, 2 Every field of a CDT, dictionary, or map must match to be treated as identical: union({a: 1, b: 2}, {a: 1, b: 2, c: 3}) returns {{a: 1, b: 2}, {a: 1, b: 2, c: 3}} union({a: 1, b: 2}, {a: 1, b: 2}) returns {{a: 1, b: 2}} Null values and empty lists Null values are included as long as they are of the correct types (nulls of an incorrect type throw a type mismatch error): union({"a", "b"}, {"c", ""}) returns an array with a, b, c, "" Empty lists are ignored as long as they are of the correct types (empty lists of an incorrect type throw a type mismatch error): union(tointeger({}), {1, 2}) returns an array with 1, 2 Scalar values Scalar values are cast to arrays with a single entry: union(1, {2, 3}) returns an array with 1, 2, 3 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 Custom record fields that evaluate in real time must be configured using one or more Custom Field functions. Process Reports Compatible Process Events Compatible Feedback Was this page helpful? SHARE FEEDBACK Loading...