Private vs Symbol vs Plain property comparison

bench.js

function bench(name, fn) {
  const a = process.hrtime.bigint();
  for (let i = 0; i < 1e7; i++)
    fn();
  const seconds = Number(process.hrtime.bigint() - a) / 1e9;
  console.log({ name, seconds });
}

class Private {
  #privateProp = 0;
}

const kSym = Symbol('kSym');
class WithSymbol {
  constructor() {
    this[kSym] = 0;
  }
}

class Plain {
  constructor() {
    this.prop = 0;
  }
}

bench('private', () => new Private());
bench('symbol', () => new WithSymbol());
bench('plain', () => new Plain());