Run results for: Private vs public class field access

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36

Browser: Chrome 137

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 10 months ago

Test name	Executions per second
Public field access	269506016.0 Ops/sec
Private field access	258287264.0 Ops/sec

Script Preparation code:

class ClassWithPublicFields {
  a;
  b;
  constructor() {
    this.a = 4;
    this.b = this.a + 3;
  }
}
window.ClassWithPublicFields = ClassWithPublicFields;

class ClassWithPrivateFields {
  #a;
  #b;
  constructor() {
    this.#a = 4;
    this.#b = this.#a + 3;
  }
}
window.ClassWithPrivateFields = ClassWithPrivateFields;

Tests:

Public field access
new ClassWithPublicFields();
Private field access
new ClassWithPrivateFields();

Run results for: Private vs public class field access

This benchmark works in latest Chrome. It will not run in Firefox, until Firefox version 90, which should come out soon.

Public field access

Private field access