Is javascript support abstract data type?

Question

Is javascript support abstract data type ?

I search lot but i did not find any answer. I think it does not support is it correct?

Answer 1

No, but you can simulate it (in ES2015+) by using new.target:

class Abstract {
  constructor(value) {
    if (new.target === Abstract) {
      throw new Error("Abstract is abstract");
    }
    this.value = value; // Proof that if the check above is false,
                        // we *do* continue to set up the instance
  }
}
class Concrete extends Abstract {
}
try {
  const a = new Abstract(1);
  console.log("Got Abstract instance, value = " + a.value);
} catch (e1) {
  console.error(e1);
}
try {
  const c = new Concrete(2);
  console.log("Got Concrete instance, value = " + c.value);
} catch (e2) {
  console.error(e2);
}

Sadly, this only produces an error when the line of code trying to do the instantiation runs, not when it's parsed/compiled.

TypeScript, which is a derivative of JavaScript that adds type checking and a few other things, has the concept of abstract classes, which are flagged up during the TypeScript compilation stage (when the TypeScript is compiled [or "transpiled"] to JavaScript); the information is also available to IDEs and such for instant feedback.