WebAssembly.Table.prototype.get()

This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

The get() prototype method of the WebAssembly.Table() object retrieves a function reference stored at a given index.

Syntax

var funcRef = table.get(index);

Parameters

index
The index of the function reference you want to retrieve.

Return value

A function reference — this is an exported WebAssembly function, a JavaScript wrapper for an underlying wasm function.

Exceptions

If index is greater than or equal to Table.prototype.length, a RangeError is thrown.

Examples

The following example (see table.html on GitHub, and view it live also) compiles and instantiates the loaded table.wasm byte code using our fetchAndInstantiate() utility function. It then retrieves the references stored in the exported table.

fetchAndInstantiate('table.wasm').then(function(instance) {
  var tbl = instance.exports.tbl;
  console.log(tbl.get(0)());  // 13
  console.log(tbl.get(1)());  // 42
});

Note how you've got to include a second function invocation operator at the end of the accessor to actually retrieve the value stored inside the reference (e.g. get(0)() rather than get(0)) — it is a function rather than a simple value.

Specifications

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

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 57 15[2] 52 (52)[1] No support 44 11
Feature Chrome for Android Android Webview Edge Mobile Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support 57 57 No support 52.0 (52)[1] No support No support 11

[1] WebAssembly is enabled in Firefox 52+, although disabled in the Firefox 52 Extended Support Release (ESR.)

[2] Currently supported behind the “Experimental JavaScript Features” flag. See this blog post for more details.

See also

Document Tags and Contributors

 Contributors to this page: chrisdavidmills, fscholz
 Last updated by: chrisdavidmills,