darthmaim / sum-by

Sum the elements of an array with an optional iteratee function

sum-by

Sum the elements of an array with an optional iteratee function

Install

npm install sum-by

This module can be used for Node.js as well as browsers using Browserify.

Usage

const _sum = require('sum-by')

_sum([1, 2, 3])
// => 6

_sum([1, undefined, 3])
// => 4

_sum([{foo: 1}, {foo: 2}, {foo: 3}], (x) => x.foo)
// => 6

_sum([{foo: 1}, {bar: 2}, {foo: 3}], (x) => x.bar)
// => 2

_sum([{foo: 1}, {bar: 2}, {foo: 3}], (x) => x.herp)
// => 0

Tests

npm test

Benchmark

npm run benchmark

	Size (uglify + gzip)	Performance	Performance (with iteratee)
sum-by	137 bytes	33,122,315 ops/sec	18,384,946 ops/sec
lodash.sumby	5,233 bytes	55,096,395 ops/sec	16,677,060 ops/sec

Licence

MIT