filter_mapping() - remove some elements of a mapping based on a func‐ tion
mapping filter_mapping( mapping map, string fun, object ob, mixed extra, ... ); mapping map_mapping( mapping map, function f, mixed extra, ... );
Returns an mapping with the same keys as map whose items have been mapped throught 'ob->fun()' or 'f'. The function is called for each element in 'arr' and the return value is put back in that spot in 'arr'. 'extra' and following are passed as parameters to the function after the item.
filter_array(3), sort_array(3), map(3)