WebAssembly.instance.exports

The exports() readonly property of the WebAssembly.Instance object prototype 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.

Syntax

var myExports = instance.exports;

Value

An object.

Examples

The following example compiles and instantiates the loaded simple.wasm byte code using the WebAssembly.instantiate() method, importing a JavaScript function into the WebAssembly Module in the process — this promise resolves to an object (obj) containing the compiled Module instance, and it's instantiated Instance instance. As you can see, we are accessing the latter's exports property to invoke the exported_func() function that is a member of the object contained by that property.

var importObject = {
  imports: {
    imported_func: function(arg) {
      console.log(arg);
    }
  }
};

fetch('simple.wasm').then(function(response) {
  response.arrayBuffer().then(function(bytes) {
    WebAssembly.instantiate(bytes, importObject).then(function(obj) {
      obj.instance.exports.exported_func();
    })
  })
});

Specifications

Specification	Status	Comment
Web Assembly JavaScript API The definition of 'instantiate()' in that specification.	Draft	Initial draft definition.

Browser compatibility

[1] Experimental support can be enabled in Chrome 51+ and Opera 38+ by going to chrome://flags and enabling the Experimental WebAssembly flag.

[2] Experimental support can be enabled in Firefox 47+ by enabling the javascript.options.wasm flag in about:config.

See also

• WebAssembly landing page.
• WebAssembly concepts
• Using the WebAssembly JavaScript API