# Vue 2 methods vs watchers vs computed properties

> Vue.js gives you methods, watchers, and computed properties. Learn when to use each one, from reacting to DOM events to deriving cached values from your data.

Author: [Flavio Copes](https://flaviocopes.com/about/) | Published: 2018-06-10 | Topics: [Vue.js](https://flaviocopes.com/tags/vue/) | Canonical: https://flaviocopes.com/vue-methods-watchers-computed-properties/

## When to use methods

- To react on some event happening in the DOM
- To call a function when something happens in your component. You can call a methods from computed properties or watchers.

## When to use computed properties

- You need to compose new data from existing data sources
- You have a variable you use in your template that's built from one or more data properties
- You want to reduce a complicated, nested property name to a more readable and easy to use one, yet update it when the original property changes
- You need to reference a value from the template. In this case, creating a computed property is the best thing because it's cached.
- You need to listen to changes of more than one data property

## When to use watchers

- You want to listen when a data property changes, and perform some action
- You want to listen to a prop value change
- You only need to listen to one specific property (you can't watch multiple properties at the same time)
- You want to watch a data property until it reaches some specific value and then do something