javascript-class

class MyClass {
  // Constructor
  constructor() {
    // Constructor body
  }

  // Instance field
  myField = "foo";

  // Static field
  static myStaticField = "bar";

  // Instance method
  myMethod() {
    // myMethod body
  }

  // Fields, methods, static fields, and static methods all have
  // "private" forms
  #myPrivateField = "bar";

  // Static method
  static myStaticMethod() {
    // myStaticMethod body
  }

  // Static block
  static {
    // Static initialization code
  }
}

references

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes#declaring_a_class