Run results for: V8 garbage collection vs out-of-scope access cost

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.5 Safari/605.1.15

Browser: Safari 17

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Benchmark engine: Benchmark.js

garbage collection

8.5M/s

out of scope access

497K/s

View exact numbers

Test name	Executions per second
✓ garbage collection	8,502,131 Ops/sec
out of scope access	496,572 Ops/sec

Script Preparation code:

var k1 = 0, k2 = 1, k3 = 2;
var k = () => {
  k1 = k2 + k3;
  k2 = k1 + k3;
  k1 = k2 + k3;
  k3 = k1 + k1;
  return k1 + k2 + k3;
};
var _k = () => {
  let _k1 = 0, _k2 = 1, _k3 = 2;
  _k1 = _k2 + _k3;
  _k2 = _k1 + _k3;
  _k1 = _k2 + _k3;
  _k3 = _k1 + _k1;
  return _k1 + _k2 + _k3;
}

Tests:

garbage collection
_k();
out of scope access
k();