You can create an easy to chain API using TypeScript classes. Learn about the thisreturn type annotation and how it plays with function chaining and class inheritance.

 

class Adder {  protected acc: number = 0;  add(num: number): Adder {    this.acc += num;    return this; // enable to chain methods  }  get result() {    return this.acc;  }}const adder = new Adder()const res = adder.add(1).add(2).result;console.log(res); // 3class Calculator extends Adder {  subtract(num: number): Calculator {    this.acc -= num;    return this;  }}const cal = new Calculator();const res2 = cal.add(1).add(2).subtract(100).result;console.log(res2) // -97

 

You can also do:

const res2 = new Calculator()  .add(1)  .add(2)  .subtract(100)  .result;console.log(res2) // -97