# Component Events {#component-events}
> This page assumes you've already read the [Components Basics](/guide/essentials/component-basics). Read that first if you are new to components.
## Emitting and Listening to Events {#emitting-and-listening-to-events}
A component can emit custom events directly in template expressions (e.g. in a `v-on` handler) using the built-in `$emit` method:
```vue-html
```
The `$emit()` method is also available on the component instance as `this.$emit()`:
```js
export default {
methods: {
submit() {
this.$emit('someEvent')
}
}
}
```
The parent can then listen to it using `v-on`:
```vue-html
```
The `.once` modifier is also supported on component event listeners:
```vue-html
```
Like components and props, event names provide an automatic case transformation. Notice we emitted a camelCase event, but can listen for it using a kebab-cased listener in the parent. As with [props casing](/guide/components/props#prop-name-casing), we recommend using kebab-cased event listeners in templates.
:::tip
Unlike native DOM events, component emitted events do **not** bubble. You can only listen to the events emitted by a direct child component. If there is a need to communicate between sibling or deeply nested components, use an external event bus or a [global state management solution](/guide/scaling-up/state-management).
:::
## Event Arguments {#event-arguments}
It's sometimes useful to emit a specific value with an event. For example, we may want the `` component to be in charge of how much to enlarge the text by. In those cases, we can pass extra arguments to `$emit` to provide this value:
```vue-html
```
Then, when we listen to the event in the parent, we can use an inline arrow function as the listener, which allows us to access the event argument:
```vue-html
```
Or, if the event handler is a method:
```vue-html
```
Then the value will be passed as the first parameter of that method:
```js
function increaseCount(n) {
count.value += n
}
```
:::tip
All extra arguments passed to `$emit()` after the event name will be forwarded to the listener. For example, with `$emit('foo', 1, 2, 3)` the listener function will receive three arguments.
:::
## Declaring Emitted Events {#declaring-emitted-events}
A component can explicitly declare the events it will emit using the [`defineEmits()`](/api/sfc-script-setup#defineprops-defineemits) macro[`emits`](/api/options-state#emits) option:
```vue
```
The `$emit` method that we used in the `` isn't accessible within the `
```
The `defineEmits()` macro **cannot** be used inside a function, it must be placed directly within `
```
If you are using TypeScript with `
```
More details: [Typing Component Emits](/guide/typescript/composition-api#typing-component-emits)
Although optional, it is recommended to define all emitted events in order to better document how a component should work. It also allows Vue to exclude known listeners from [fallthrough attributes](/guide/components/attrs#v-on-listener-inheritance), avoiding edge cases caused by DOM events manually dispatched by 3rd party code.
:::tip
If a native event (e.g., `click`) is defined in the `emits` option, the listener will now only listen to component-emitted `click` events and no longer respond to native `click` events.
:::
## Events Validation {#events-validation}
Similar to prop type validation, an emitted event can be validated if it is defined with the object syntax instead of the array syntax.
To add validation, the event is assigned a function that receives the arguments passed to the `this.$emit``emit` call and returns a boolean to indicate whether the event is valid or not.