Understanding computed setters

By default, computed data is a getter only, which means it will only output the outcome of your expression. In some practical scenarios, when a computed property is mutated, you may need to trigger an external API or mutate the original data elsewhere in the project. The function performing this feature is called a setter.

Using a setter in a computed property allows you to reactively listen to data and trigger a callback (setter) that contains the returned value from the getter, which can optionally be used in the setter.

But first, let’s look at JavaScript ES5’s getter and setter. Starting from ES5, you can use the built-in getter and setter to define Object accessors, such as the following:

• get to bind the Object property to a function that returns a value for that property whenever it is looked up, as shown here:

  const obj  = {
    get example() {
      return 'Getter'
   ...