Run results for: Private vs public class field access

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.0 Safari/537.36

Browser: Chrome 135

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Public field access	227365616.0 Ops/sec
Private field access	211516432.0 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