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sumBy

_.sumBy(iteratee, array) # Ⓢ [Ⓣ][1] Ⓝ

This method is like _.sum except that it accepts iteratee which is



invoked for each element in array to generate the value to be summed.



The iteratee is invoked with one argument: (value).

Since​

4.0.0

Arguments​

  1. iteratee (Function): The iteratee invoked per element.
  2. array (Array): The array to iterate over.

Returns​

(number): Returns the sum.

Example​

var objects = [{ 'n': 4 }, { 'n': 2 }, { 'n': 8 }, { 'n': 6 }];

_.sumBy(function(o) { return o.n; }, objects);
// => 20

// The `_.property` iteratee shorthand.
_.sumBy('n', objects);
// => 20