func:unique

unique(val, key: null)

Return the unique items in a collection. If val is a List then return List.unique. If val is a Grid then return Grid.unique where key must be a column name or list of column names.

Examples:

[1, 1, 2, 2].unique                 >> [1, 2]
grid.unique("geoState")             >> unique states
grid.unique(["geoCity", geoState"]) >> city,state combos