reduce¶
Traverse items of a collection while applying a lambda allowing data to be combined in a particular way to return a result.
reduce can be applied on a map< K, V >, list< T >, or set< T >.
Parameters:
| No. | Type | Comments |
|---|---|---|
| 1 | map< K, V >, list< T > or set< T > | The object on which the reduce should be applied |
| 2 | Initial value of type R | An initial value for the accumulator |
| 3 | A lambda that accepts 2 or 3 parameter | The 1st lambda parameter will always be the current accumulator. When 1st parameter to reduce is a list< T > or set< T >,then the 2nd parameter to lambda is one of its elements.When 1st parameter to map is a map< K, V >, the lambda accepts 3 parameters - accumulator, entry key and entry value. |
Returns:
The final value of the accumulator, which was the 2nd argument to reduce.
Usages:
reduce( v:list<T>, accumulator : R, ( acc, e ) => result : R ) : Rreduce( v:set<T>, accumulator : R, ( acc, e ) => result : R ) : Rreduce( v:map<K, V>, accumulator : R, (acc, k, v) => result : R ) : R