Comparison of js string testing techniques

bench.js

var allAttrs = ["abbr","accept","accept-charset","accesskey","action","alt","async","autocomplete","autocomplete","autofocus","autoplay","border","challenge","charset","charset","checked","cite","class","cols","colspan","content","contenteditable","controls","coords","crossorigin","data","datetime","datetime","default","defer","dir","dir","dirname","disabled","download","enctype","for","for","form","formaction","formenctype","formmethod","formnovalidate","formtarget","headers","height","hidden","high","href","href","href","hreflang","http-equiv","id","ismap","keytype","kind","label","lang","list","loop","low","manifest","max","max","maxlength","media","mediagroup","method","min","min","minlength","multiple","muted","name","name","name","name","name","name","novalidate","optimum","pattern","placeholder","poster","preload","readonly","rel","required","reversed","rows","rowspan","sandbox","spellcheck","scope","selected","shape","size","sizes","span","src","srcdoc","srclang","start","step","style","tabindex","target","target","target","title","title","title","title","title","translate","type","type","type","type","type","typemustmatch","usemap","value","value","value","value","value","value","width","wrap"];

var booleanAttrsArray = ["allowfullscreen", "async", "autofocus", "autoplay", "checked", "compact", "controls", "declare", "default", "defaultchecked", "defaultmuted", "defaultselected", "defer", "disabled", "draggable", "enabled", "formnovalidate", "hidden", "indeterminate", "inert", "ismap", "itemscope", "loop", "multiple", "muted", "nohref", "noresize", "noshade", "novalidate", "nowrap", "open", "pauseonexit", "readonly", "required", "reversed", "scoped", "seamless", "selected", "sortable", "spellcheck", "translate", "truespeed", "typemustmatch", "visible"];

var booleanAttrsHash = {
  allowfullscreen: 1,
  async: 1,
  autofocus: 1,
  autoplay: 1,
  checked: 1,
  compact: 1,
  controls: 1,
  declare: 1,
  default: 1,
  defaultchecked: 1,
  defaultmuted: 1,
  defaultselected: 1,
  defer: 1,
  disabled: 1,
  draggable: 1,
  enabled: 1,
  formnovalidate: 1,
  hidden: 1,
  indeterminate: 1,
  inert: 1,
  ismap: 1,
  itemscope: 1,
  loop: 1,
  multiple: 1,
  muted: 1,
  nohref: 1,
  noresize: 1,
  noshade: 1,
  novalidate: 1,
  nowrap: 1,
  open: 1,
  pauseonexit: 1,
  readonly: 1,
  required: 1,
  reversed: 1,
  scoped: 1,
  seamless: 1,
  selected: 1,
  sortable: 1,
  spellcheck: 1,
  translate: 1,
  truespeed: 1,
  typemustmatch: 1,
  visible: 1
};

var booleanAttrsRegex = /^(?:a(?:llowfullscreen|sync|uto(?:focus|play))|c(?:hecked|o(?:mpact|ntrols))|d(?:e(?:clare|f(?:ault(?:(?:check|(?:mu|selec)t)ed)?|er))|isabled|raggable)|enabled|formnovalidate|hidden|i(?:n(?:determinate|ert)|smap|temscope)|loop|mu(?:ltiple|ted)|no(?:href|resize|shade|validate|wrap)|open|pauseonexit|re(?:adonly|(?:quir|vers)ed)|s(?:coped|e(?:amless|lected)|ortable|pellcheck)|t(?:r(?:anslate|uespeed)|ypemustmatch)|visible)$/;

var booleanAttrsSet = new Set(booleanAttrsArray);

var n = 10e3;

function bench(t, f) {
  var s = Date.now();
  for (var i = 0; i < n; i++) {
    f();
  }
  var e = Date.now() - s;
  console.log(t, (n/1000) + "k", e, "mS");
}

bench("impelling", function() {
  var res;
  for(var i = 0; i < allAttrs.length; i++) {
    res = allAttrs.indexOf(allAttrs[i]);
  }
});

bench("array search", function() {
  var res;
  for(var i = 0; i < allAttrs.length; i++) {
    res = booleanAttrsArray.indexOf(allAttrs[i]);
  }
});

bench("hash lookup", function() {
  var res;
  for(var i = 0; i < allAttrs.length; i++) {
    res = booleanAttrsHash[allAttrs[i]];
  }
});

bench("regex match", function() {
  var res;
  for(var i = 0; i < allAttrs.length; i++) {
    res = booleanAttrsRegex.test(allAttrs[i]);
  }
});

bench("set lookup", function() {
  var res;
  for(var i = 0; i < allAttrs.length; i++) {
    res = booleanAttrsSet.has(allAttrs[i]);
  }
});

@nunocastromartins: I added test using Set too. The sets works really much faster in v8-based environments (Node, Chromium).

Finding a real use case for something less commonly used it exciting.

Finding a techniques for optimization of hot code path is exciting.