_bench-array-join-vs-string-concat.js

const Benchmark = require("benchmark");

displayIntro()

const N = 1000;

const A = 'a'
const B = 'b'
const C = 'c'

new Benchmark.Suite("array-join-vs-string", createConf())
  .add("array join", () => {
    let i = -1;
    while (++i < N) [A, B, C].join(' ');
  })
  .add("str concat", () => {
    let i = -1;
    while (++i < N) A + ' ' + B + ' ' + C
  })
  .add("template literal", () => {
    let i = -1;
    while (++i < N) `${A} ${B} ${C}`
  })
  .run();

function createConf() {
  return {
    onComplete(e) {
      this.map((bench) =>
        console.log(
          JSON.stringify(
            {
              name: bench.name,
              hz: bench.hz.toFixed(2),
              relativeMarginOfError: `${bench.stats.rme.toFixed(2)}%`,
              runs: bench.stats.sample.length,
            }
          )
        )
      );
    },
    onError(e) {
      console.error(e.target.error);
    }
  }
}

function displayIntro() {
  console.log(JSON.stringify({ nodeVersion: process.version }))
}

_results.ldjson

{"nodeVersion":"v12.16.2"}
{"name":"array join","hz":"5093.61","relativeMarginOfError":"0.82%","runs":90}
{"name":"str concat","hz":"1123945.33","relativeMarginOfError":"0.63%","runs":90}
{"name":"template literal","hz":"1117304.79","relativeMarginOfError":"1.68%","runs":92}

package.json

{
  "name": "bench-array-join-vs-string-concat",
  "version": "1.0.0",
  "description": "",
  "main": "_bench-array-join-vs-string-concat.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "bench": "node _bench-array-join-vs-string-concat.js | tee _results.ldjson"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "benchmark": "^2.1.4"
  }
}

yarn.lock

# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
# yarn lockfile v1


benchmark@^2.1.4:
  version "2.1.4"
  resolved "https://registry.yarnpkg.com/benchmark/-/benchmark-2.1.4.tgz#09f3de31c916425d498cc2ee565a0ebf3c2a5629"
  integrity sha1-CfPeMckWQl1JjMLuVloOvzwqVik=
  dependencies:
    lodash "^4.17.4"
    platform "^1.3.3"

lodash@^4.17.4:
  version "4.17.15"
  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.15.tgz#b447f6670a0455bbfeedd11392eff330ea097548"
  integrity sha512-8xOcRHvCjnocdS5cpwXQXVzmmh5e5+saE2QGoeQmbKmRS6J3VQppPOIt0MnmE+4xlZoumy0GPG0D0MVIQbNA1A==

platform@^1.3.3:
  version "1.3.5"
  resolved "https://registry.yarnpkg.com/platform/-/platform-1.3.5.tgz#fb6958c696e07e2918d2eeda0f0bc9448d733444"
  integrity sha512-TuvHS8AOIZNAlE77WUDiR4rySV/VMptyMfcfeoMgs4P8apaZM3JrnbzBiixKUv+XR6i+BXrQh8WAnjaSPFO65Q==