Lodash

sumBy

Math
since 4.0.0

Arguments

  • Array The array to iterate over.
  • Function The iteratee invoked per element.

Returns

number the sum.

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).

Example of Lodash _.sumBy

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

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

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