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 | 148 bytes | 56,339,337 ops/sec | 31,280,534 ops/sec | | lodash.sumby | 5,233 bytes | 53,324,787 ops/sec | 16,245,337 ops/sec |

Licence

MIT