Static Constructor in Javascript ES6

Question

In ES6, I can create static methods like below. But I need to define a static constructor but no success. I need something that runs only once when the class is loaded. I Is

Answer 1

If you insist on a static constructor: Define a static method and invoke it after the class definition.

class Foo {
  static staticConstructor() {
    console.log('Foo has been constructed statically!');
  }
}

Foo.staticConstructor()

Of course this is not really necessary. Except mabye to clearly express the notion of a static constructor. However this smells like Java.

Felix proposed a fine solution by putting code before or after the class definition.

For example: Do you want to pre-calculate some static members? Just assign the calculation result after the class definition!

class Foo {}

Foo.preCalculated = calculate();

function calculate() {
  console.log('Do some hard work here');
  return 'PRECALCULATED';
}