The created hook allows you to add code which is run if the Vue instance is created. The steps in a Vue Lifecycle. are: beforeCreate, created, beforeMount, mounted, beforeUpdate, updated, beforeDestroy,destroyed.
You can hook directly into these steps.
If you link the created hook, you can directly execute code as soon as the program starts.(This code will be run as soon the Vue instance exists).
If you create your app.js you can define the created hook:
Load your page and open Chrome Developer Tools (F12) or Firefox Dev Tools (F12).
If you load the page you’ll see the message ‘created called’, which is the code executed in created.