4.17.11
3.10.1
2.4.2
1.3.1

_.sumBy(array, [iteratee=_.identity])

sourcenpm package

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

argument
array
[iteratee=_.identity]
type
Array
Function
description
The array to iterate over.
The iteratee invoked per element.

Returns

(array)

Example

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

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