---
sidebar_label: CommonEventEmitter.on
---

# CommonEventEmitter.on() method

#### Signature:

```typescript
interface CommonEventEmitter {
  on<Key extends keyof Events>(type: Key, handler: Handler<Events[Key]>): this;
}
```

## Parameters

<table><thead><tr><th>

Parameter

</th><th>

Type

</th><th>

Description

</th></tr></thead>
<tbody><tr><td>

type

</td><td>

Key

</td><td>

</td></tr>
<tr><td>

handler

</td><td>

[Handler](./puppeteer.handler.md)&lt;Events\[Key\]&gt;

</td><td>

</td></tr>
</tbody></table>
**Returns:**

this