Vue JS — Computed Properties v/s Watchers
Vue.js is a popular JavaScript framework that allows developers to build robust, reactive web applications with ease.
One of the key features of Vue.js is its ability to define computed properties and watchers, which can help to manage the state of your application and respond to changes in your data.
Computed Properties
Computed properties are properties that are derived from other properties in your Vue instance or component. They are similar to methods, but with some important differences. Computed properties are cached based on their dependencies, which means that if the data they depend on doesn’t change, the computed property won’t be recomputed. This can be a useful optimization when working with complex data.
Here’s an example of a computed property in Vue.js:
In this example, we have a component that displays a person’s full name based on their first and last name. The fullName computed property concatenates the firstName and lastName data properties and returns the result.
Watchers
Watchers are functions that watch for changes in your data and perform some action when a change is detected. They can be used to perform asynchronous operations or to update the DOM based on changes in your data.
Here’s an example of a watcher in Vue.js:
In this example, we have a component with an input field that allows the user to search for items. The search data property is watched, and when a change is detected, an AJAX request is made to the server to retrieve the search results. The results data property is then updated with the new data, which causes the list of search results to be re-rendered.
In summary, computed properties and watchers are powerful tools in Vue.js for managing the state of your application and responding to changes in your data. Computed properties can help to optimize the performance of your application by caching the results of expensive calculations, while watchers can be used to perform asynchronous operations or update the DOM in response to changes in your data.
