Get javascript code and modify it to execute chainable

I want to change my code to execute chaining. this is my code:

let stepCount = {
    step: 0,
    up() {
        this.step++;
    },
    down() {
        this.step--;
    },
    showStep: function () {
       return this.step;
    }
};

How should I change it? I want to execute this code to get answer

stepCount.up().up().down().up();

>Solution :

you just need to return the current object from each function like this

let stepCount = {
  step: 0,
  up() {
    this.step++;
    return this;
  },
  down() {
    this.step--;
    return this
  },
  showStep: function() {
    console.log(this.step)
    return this;
  }
};

stepCount.up().up().down().showStep().down().showStep();