plain-function-vs-prototyped-function.js

#!/usr/bin/env node

// extending string and calling functions on it sucks

function a() { }

String.prototype.a = a;
var str = ""
  , strObj = new String(str);

Array.prototype.a = a;
var arr = [];

RegExp.prototype.a = a;
var rgx = /a/;

a.prototype.a = a;
var obj = new a();

exports.compare = {
  "plain": function() {
    a();
  },
  "string (literal) prototype": function() {
    str.a();
  },
  "string (coerced literal) prototype": function() {
    String(str).a();
  },
  "string (object) prototype": function() {
    strObj.a();
  },
  "array prototype": function() {
    arr.a();
  },
  "regex prototype": function() {
    rgx.a();
  },
  "object prototype": function() {
    obj.a();
  }
};

require("bench").runMain();

/*
$ node plain-function-vs-prototyped-function.js 
benchmarking plain-function-vs-prototyped-function.js
Please be patient.
Scores: (bigger is better)

plain
Raw:
 > 46578.42157842158
 > 45553.446553446556
 > 47217.782217782216
 > 42516.48351648352
 > 47426.57342657343
Average (mean) 45858.541458541455

object prototype
Raw:
 > 40020.97902097902
 > 42557.442557442555
 > 39831.168831168834
 > 43007.992007992005
 > 42729.27072927073
Average (mean) 41629.370629370635

string (object) prototype
Raw:
 > 40307.692307692305
 > 42668.331668331666
 > 43196.803196803194
 > 41781.218781218784
 > 39830.16983016983
Average (mean) 41556.843156843155

array prototype
Raw:
 > 39521.47852147852
 > 41196.803196803194
 > 40234.76523476523
 > 42425.57442557443
 > 41656.343656343655
Average (mean) 41006.993006993005

regex prototype
Raw:
 > 39952.04795204795
 > 33506.493506493505
 > 41236.76323676324
 > 41387.61238761239
 > 39808.191808191805
Average (mean) 39178.22177822177

string (literal) prototype
Raw:
 > 335.99202392821536
 > 1282.7172827172826
 > 1296.7032967032967
 > 1473.5264735264736
 > 365.1741293532338
Average (mean) 950.8226412457004

string (coerced literal) prototype
Raw:
 > 1304.6953046953047
 > 1238.7612387612387
 > 272.72727272727275
 > 332.00398803589235
 > 1192.807192807193
Average (mean) 868.1989994053802

Winner: plain
Compared with next highest (object prototype), it's:
9.22% faster
1.1 times as fast
0.04 order(s) of magnitude faster

Compared with the slowest (string (coerced literal) prototype), it's:
98.11% faster
52.82 times as fast
1.72 order(s) of magnitude faster
 */

Whoah. That is a f'huge difference.

yeah, it's kinda scary.

updated with the results of a plain new object, which is totally fine. not sure why extending strings sucks so much.

threw in extending Array and RegExp, also no sweat. still just String, sitting there peeing in the pool.