在此页

• 构造函数
• 实例特性
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

A WebAssembly.Instance object is a stateful, executable instance of a WebAssembly.Module . Instance objects contain all the Exported WebAssembly functions that allow calling into WebAssembly code from JavaScript.

构造函数

WebAssembly.Instance()

创建新的 Instance 对象。

实例特性

Instance.prototype.exports

Returns an object containing as its members all the functions exported from the WebAssembly module instance, to allow them to be accessed and used by JavaScript. Read-only.

范例

Synchronously instantiating a WebAssembly module

WebAssembly.Instance() constructor function can be called to synchronously instantiate a given WebAssembly.Module object, for example:

const importObject = {
  imports: {
    imported_func: function(arg) {
      console.log(arg);
    }
  }
};
fetch('simple.wasm').then(response =>
  response.arrayBuffer()
).then(bytes => {
  let mod = new WebAssembly.Module(bytes);
  let instance = new WebAssembly.Instance(mod, importObject);
  instance.exports.exported_func();
})
					

The preferred way to get an Instance is asynchronously, for example using the WebAssembly.instantiateStreaming() function like this:

const importObject = {
  imports: {
    imported_func: function(arg) {
      console.log(arg);
    }
  }
};
WebAssembly.instantiateStreaming(fetch('simple.wasm'), importObject)
.then(obj => obj.instance.exports.exported_func());
					

This also demonstrates how the exports property is used to access exported functions.

规范

规范
WebAssembly JavaScript 接口 The definition of 'Instance' in that specification.

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. 更新 GitHub 上的兼容性数据

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
Instance	Chrome 57	Edge 16	Firefox 52 52 Disabled in the Firefox 52 Extended Support Release (ESR).	IE No	Opera 44	Safari 11	WebView Android 57	Chrome Android 57	Firefox Android 52 52 Disabled in the Firefox 52 Extended Support Release (ESR).	Opera Android 43	Safari iOS 11	Samsung Internet Android 7.0	nodejs 8.0.0
Instance() 构造函数	Chrome 57	Edge 16	Firefox 52 52 Disabled in the Firefox 52 Extended Support Release (ESR).	IE No	Opera 44	Safari 11	WebView Android 57	Chrome Android 57	Firefox Android 52 52 Disabled in the Firefox 52 Extended Support Release (ESR).	Opera Android 43	Safari iOS 11	Samsung Internet Android 7.0	nodejs 8.0.0
exports	Chrome 57	Edge 16	Firefox 52 52 Disabled in the Firefox 52 Extended Support Release (ESR).	IE No	Opera 44	Safari 11	WebView Android 57	Chrome Android 57	Firefox Android 52 52 Disabled in the Firefox 52 Extended Support Release (ESR).	Opera Android 43	Safari iOS 11	Samsung Internet Android 7.0	nodejs 8.0.0

图例

完整支持

完整支持

不支持

不支持

见实现注意事项。

另请参阅

• WebAssembly 概述页面
• WebAssembly 概念
• 使用 WebAssembly JavaScript API

元数据

• 最后修改： May 28, 2020

相关话题

1. 标准内置对象
2. WebAssembly
3. 方法
   1. WebAssembly.compile()
   2. WebAssembly.compileStreaming()
   3. WebAssembly.instantiate()
   4. WebAssembly.instantiateStreaming()
   5. WebAssembly.validate()
4. 相关页面：
5. WebAssembly.Module
6. WebAssembly.Global
7. WebAssembly.Instance
8. WebAssembly.Memory
9. WebAssembly.Table
10. WebAssembly.CompileError
11. WebAssembly.LinkError
12. WebAssembly.RuntimeError
13. 继承：
14. Object
15. 特性
    1. Object.prototype.__proto__
    2. Object.prototype.constructor
16. 方法
    1. Object.prototype.__defineGetter__()
    2. Object.prototype.__defineSetter__()
    3. Object.prototype.__lookupGetter__()
    4. Object.prototype.__lookupSetter__()
    5. Object.prototype.hasOwnProperty()
    6. Object.prototype.isPrototypeOf()
    7. Object.prototype.propertyIsEnumerable()
    8. Object.prototype.toLocaleString()
    9. Object.prototype.toSource()
    10. Object.prototype.toString()
    11. Object.prototype.valueOf()
    12. Object.setPrototypeOf()