Can I add getters and setters using defineProperty method?

Yes, You can use the Object.defineProperty() method to add Getters and Setters. For example, the below counter object uses increment, decrement, add and subtract properties,

      var obj = { counter: 0 };

      // Define getters
      Object.defineProperty(obj, "increment", {
        get: function () {
          this.counter++;
          return this.counter;
        },
      });
      Object.defineProperty(obj, "decrement", {
        get: function () {
          this.counter--;
          return this.counter;
        },
      });

      // Define setters
      Object.defineProperty(obj, "add", {
        set: function (value) {
          this.counter += value;
        },
      });
      Object.defineProperty(obj, "subtract", {
        set: function (value) {
          this.counter -= value;
        },
      });

      obj.add = 10;
      obj.subtract = 5;
      console.log(obj.increment); //6
      console.log(obj.decrement); //5