# Lifecycle Hooks

This guide assumes that you have already read the Composition API Introduction and Reactivity Fundamentals. Read that first if you are new to Composition API.

Watch a free video about Lifecycle Hooks on Vue Mastery

You can access a component's lifecycle hook by prefixing the lifecycle hook with "on".

The following table contains how the lifecycle hooks are invoked inside of setup():

Options API Hook inside setup
beforeCreate Not needed*
created Not needed*
beforeMount onBeforeMount
mounted onMounted
beforeUpdate onBeforeUpdate
updated onUpdated
beforeUnmount onBeforeUnmount
unmounted onUnmounted
errorCaptured onErrorCaptured
renderTracked onRenderTracked
renderTriggered onRenderTriggered
activated onActivated
deactivated onDeactivated

TIP

Because setup is run around the beforeCreate and created lifecycle hooks, you do not need to explicitly define them. In other words, any code that would be written inside those hooks should be written directly in the setup function.

These functions accept a callback that will be executed when the hook is called by the component:

// MyBook.vue

export default {
  setup() {
    // mounted
    onMounted(() => {
      console.log('Component is mounted!')
    })
  }
}
1
2
3
4
5
6
7
8
9
10

Deployed on Netlify.
Last updated: 2021-05-14, 13:38:29 UTC