Types · hard

49. Polymorphic this types

Referencing the current class type fluently.

Write a fluent class `Calc` where methods return `this`.

Required in your answer: add(n: number): thisreturn this

Transpiled, then run in a sandbox

class Calc {
  val = 0;
  add(n: number): this {
    this.val += n;
    return this;
  }
}

Output appears here.