View this page in the latest version of Appian. a!flatten() Function Share Share via LinkedIn Reddit Email Copy Link Print On This Page Function a!flatten( array ) Converts an array that contains other arrays into an array of single items. Parameters Keyword Type Description array Any Type Array Array to be flattened. Returns Any Type Array Usage considerations Understanding results a!flatten() removes nesting from arrays, such as those created by looping functions. When passed a simple array, a!flatten() returns it unmodified. Nulls are not removed from lists. Use reject() and isnull() to easily remove nulls from a flattened list. a!flatten() always returns an array, so when passed a single item, a!flatten() returns an array containing that item. When passed an empty or null array, a!flatten() returns an empty array. If the passed array is type Any Type, a!flatten() returns an array of the appropriate type. Examples Remove nesting from arrays a!forEach(items: {1, 2, 3}, expression: enumerate(fv!item)) returns a 3 item list consisting of {0}, {0, 1}, and {0, 1, 2} a!flatten(a!forEach(items: {1, 2, 3}, expression: enumerate(fv!item))) returns {0, 0, 1, 0, 1, 2} Remove only array nesting Only array nesting is removed when using a!flatten. Nested maps, dictionaries, and data types retain their structure. 1 2 3 4 5 6 7 a!flatten( { a!map( id: 1 ), a!map( id: 2 ), a!map( id: 3, address: a!map( street: "Main Street", number: 101 ) ) } ) returns: 1 2 3 4 5 { a!map( id: 1 ), a!map( id: 2 ), a!map( id: 3, address: a!map( street: "Main Street", number: 101 ) ) } Retaining data types typename(typeof(a!flatten({a: {1, 2, 3}}.a))) returns "List of Number (Integer)" typename(typeof(a!flatten({a: {1, 2, "apple"}}.a))) returns "List of Variant" 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 Incompatible You cannot use this function to configure a process report. Process Events Incompatible You cannot use this function to configure a process event node, such as a start event or timer event. Feedback Was this page helpful? SHARE FEEDBACK Loading...