Run results for: isNumber: regex vs isNaN

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:107.0) Gecko/20100101 Firefox/107.0

Browser: Firefox 107

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
isNaN	5.2 Ops/sec
regex	3.7 Ops/sec

Script Preparation code:

window.case1 = new Proxy({}, {
  get(t, p, r) {
    if (typeof p === 'string' && !isNaN(p)) {
      return +p
    }
    else {
      return Reflect.get(t, p, r)
    }
  }
});
window.case2 = new Proxy({}, {
  get(t, p, r) {
    if (/^\d+$/.test(p)) {
      return +p
    }
    else {
      return Reflect.get(t, p, r)
    }
  }
});
window.gabage1 = 0;
window.gabage2 = 0;

Tests:

isNaN
for (let i = 0; i < 1e6;i++) { gabage1 =+ case1[i]; }
regex
for (let i = 0; i < 1e6;i++) { gabage2 += case2[i]; }

Run results for: isNumber: regex vs isNaN

judge an object property key is a number

isNaN

regex