Run results for: fast Deep Equal vs JSON.stringify Equality Comparison for large arrays of nested numbers

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/129.0.6668.69 Mobile/15E148 Safari/604.1

Browser: Chrome Mobile iOS 129

Operating system: iOS 18.1

Device Platform: Mobile

Date tested: one year ago

Test name	Executions per second
fast deep equals same	3301.5 Ops/sec
fast deep equals similar	3021235.8 Ops/sec
fast deep equals different	2911689.5 Ops/sec
stringify same	906.9 Ops/sec
stringify similar	926.5 Ops/sec
stringify different	910.6 Ops/sec

Script Preparation code:

'use strict';

// do not edit .js files directly - edit src/index.jst


  var envHasBigInt64Array = typeof BigInt64Array !== 'undefined';


window.fdeq = function equal(a, b) {
  if (a === b) return true;

  if (a && b && typeof a == 'object' && typeof b == 'object') {
    if (a.constructor !== b.constructor) return false;

    var length, i, keys;
    if (Array.isArray(a)) {
      length = a.length;
      if (length != b.length) return false;
      for (i = length; i-- !== 0;)
        if (!equal(a[i], b[i])) return false;
      return true;
    }


    if ((a instanceof Map) && (b instanceof Map)) {
      if (a.size !== b.size) return false;
      for (i of a.entries())
        if (!b.has(i[0])) return false;
      for (i of a.entries())
        if (!equal(i[1], b.get(i[0]))) return false;
      return true;
    }

    if ((a instanceof Set) && (b instanceof Set)) {
      if (a.size !== b.size) return false;
      for (i of a.entries())
        if (!b.has(i[0])) return false;
      return true;
    }

    if (ArrayBuffer.isView(a) && ArrayBuffer.isView(b)) {
      length = a.length;
      if (length != b.length) return false;
      for (i = length; i-- !== 0;)
        if (a[i] !== b[i]) return false;
      return true;
    }


    if (a.constructor === RegExp) return a.source === b.source && a.flags === b.flags;
    if (a.valueOf !== Object.prototype.valueOf) return a.valueOf() === b.valueOf();
    if (a.toString !== Object.prototype.toString) return a.toString() === b.toString();

    keys = Object.keys(a);
    length = keys.length;
    if (length !== Object.keys(b).length) return false;

    for (i = length; i-- !== 0;)
      if (!Object.prototype.hasOwnProperty.call(b, keys[i])) return false;

    for (i = length; i-- !== 0;) {
      var key = keys[i];

      if (!equal(a[key], b[key])) return false;
    }

    return true;
  }

  // true if both NaN, false otherwise
  return a!==a && b!==b;
};

window.foo = Array.from({length: 4000}, () => ([Math.random() * 40, Math.random() * 40]));
window.foo2 = JSON.parse(JSON.stringify(window.foo.slice()));
window.fox = JSON.parse(JSON.stringify(window.foo.slice(0, 3000))).concat(Array.from({length: 1000}, () => ([Math.random() * 40, Math.random() * 40])));
window.bar = Array.from({length: 4000}, () => ([Math.random() * 40, Math.random() * 40]));

Tests:

fast deep equals same
fdeq(window.foo, window.foo2);
fast deep equals similar
fdeq(window.foo, window.fox);
fast deep equals different
fdeq(window.foo, window.bar);
stringify same
JSON.stringify(window.foo) === JSON.stringify(window.foo2)
stringify similar
JSON.stringify(window.foo) === JSON.stringify(window.fox)
stringify different
JSON.stringify(window.foo) === JSON.stringify(window.bar)

Run results for: fast Deep Equal vs JSON.stringify Equality Comparison for large arrays of nested numbers

Test on deep equality checking performance

fast deep equals same

fast deep equals similar

fast deep equals different

stringify same

stringify similar

stringify different