WebSocket.extensions是只读属性，返回服务器已选择的扩展值。目前，链接可以协定的扩展值只有空字符串或者一个扩展列表。
The WebSocket.extensions read-only property returns the extensions selected by the server. This is currently only the empty string or a list of extensions as negotiated by the connection.
语法
var extensions = aWebSocket.extensions;
返回值
A DOMString.
规范
| Specification | Status | Comment |
|---|---|---|
| HTML Living Standard WebSocket: extensions |
Living Standard | Initial definition |
浏览器兼容性
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Update compatibility data on GitHub
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
extensions | Chrome Full support Yes | Edge Full support 12 | Firefox Full support 8 | IE ? | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support 8 | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android ? |
Legend
- Full support
- Full support
- Compatibility unknown
- Compatibility unknown