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WebAssembly.Memory.prototype.buffer

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 buffer prototype property of the Memory object returns the buffer contained in the memory.

memory.buffer

Examples

The following example (see memory.html on GitHub, and view it live also) fetches and instantiates the loaded memory.wasm byte code using our fetchAndInstantiate() utility function. It then exports a memory from the module, stores some values in it, then exports a function and uses it to sum some values.

fetchAndInstantiate('memory.wasm').then(function(instance) {
  var i32 = new Uint32Array(instance.exports.mem.buffer);
  for (var i = 0; i < 10; i++) {
    i32[i] = i;
  }
  var sum = instance.exports.accumulate(0, 10);
  console.log(sum);
});

Specifications

Specification Status Comment
Web Assembly JavaScript API
The definition of 'buffer' 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,