isList

Returns true when the class of this column's type is List, i.e., the column holds List<*> (or List<*>?) values.

Only the List class itself is matched: a column of a List subtype (like ArrayList<*>) or of another Collection type (like Set<*>) is not considered a list column.

Examples

val ages = df.groupBy("city").aggregate { this["age"].toList() into "ages" }

ages["ages"].isList() // true, `ages` holds lists of ages
ages["city"].isList() // false