reduce
Collection
since 0.1.0
Returns
* the accumulated value.
Reduces collection to a value which is the accumulated result of running
each element in collection thru iteratee, where each successive
invocation is supplied the return value of the previous. If accumulator
is not given, the first element of collection is used as the initial
value. The iteratee is invoked with four arguments:
(accumulator, value, index|key, collection).
Many lodash methods are guarded to work as iteratees for methods like
_.reduce, _.reduceRight, and _.transform.
The guarded methods are:
assign, defaults, defaultsDeep, includes, merge, orderBy,
and sortBy
Example of Lodash _.reduce
_.reduce([1, 2], function(sum, n) {
return sum + n;
}, 0);
// => 3
_.reduce({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) {
(result[value] || (result[value] = [])).push(key);
return result;
}, {});
// => { '1': ['a', 'c'], '2': ['b'] } (iteration order is not guaranteed)