Explain Life cycle of Vue Instance.

The Life cycle of each Vue instance goes through a series of initialization steps when it is created.
– for example, it needs to set up data observation, compile the template, and create the necessary data bindings. Along the way, it will also invoke some lifecycle hooks, which give us the opportunity to execute custom logic. For example, the created hook is called after the instance is created:

new Vue({
  data: {
    a: 1
  },
  created: function () {
    // `this` points to the vm instance
    console.log('a is: ' + this.a)
  }
})
// => "a is: 1"

There are also other hooks which will be called at different stages of the instance’s lifecycle, for example compiled, ready and destroyed. All lifecycle hooks are called with their this context pointing to the Vue instance invoking it. Some users may have been wondering where the concept of “controllers” lives in the Vue.js world, and the answer is: there are no controllers in Vue.js. Your custom logic for a component would be split among these lifecycle hooks.

Lifecycle Diagram

Below diagram shows complete life cycle of Vue Instance

Source: https://v1.vuejs.org/guide/instance.html#Instance-Lifecycle

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