The
invalueset function determines whether an item's current value is within the permissible ranges of a value set. In addition to specifying the
item_name, an optional argument,
value_set_name, allows you to specify in which value set to check if the item's value is within the permissible ranges. If no value set is specified, the item's current value set is used.
The function returns a logical value of 1 (true) if the item's value is within the value set's ranges and 0 (false) otherwise. If the item has no value set, the function return 1 (true).