I have a class that looks like this:
class Foo {
constructor(arg1, arg2) {
// ...
this._some_obj = new SomeObj({
param1: arg1,
param2: arg2
});
}
// ...
}
module.exports = Foo;
Now I want to do the same thing but with _some_obj shared between all instances of the class.
After searching around I'm unclear as to the correct way to do this in ES6.
As known from ES5, you can just put it on the class's prototype object:
export class Foo {
constructor(arg1, arg2) {
…
}
…
}
Foo.prototype._some_obj = new SomeObj({
param1: val1,
param2: val2
});
Or directly on Foo, if you don't need to access it as a property on instances.
Math.prototype.min = is not a good property to overwrite, because it effects every instance of Math.min
arg1 and arg2 to be available to the constructor of SomeObj. I think Foo.prototype._some_obj would be created before the constructor is ever called.Use static to have class properties.
class MyClass {
static myStaticProp = 42;
constructor() {
console.log(MyClass.myStaticProp); // Prints '42'
}
}
N.B: this is a feature already implemented in Babel, but is still experimental as only at the 1st proposal stage.
static is only for member functions not data.myStaticProp with the arguments to the constructor.
if (this.myStaticProp === null) { ... }
Object.defineProperties(MyClass, ...) would behave much differently.