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 grow() protoype method of the Memory object increases the size of the memory instance by a specified number of WebAssembly pages.
Syntax
memory.grow(number);
Parameters
- number
- The number of WebAssembly pages you want to grow the memory by (each one is 64KiB in size).
Return value
The previous size of the memory, in units of WebAssembly pages.
Examples
The following example creates a new WebAssembly Memory instance with an initial size of 1 page (64KiB), and a maximum size of 10 pages (640KiB).
var memory = new WebAssembly.Memory({initial:1, maximum:10});
We can then grow the instance by one page like so:
const bytesPerPage = 64 * 1024; console.log(memory.buffer.byteLength / bytesPerPage); // "1" console.log(memory.grow(1)); // "1" console.log(memory.buffer.byteLength / bytesPerPage); // "2"
Note the return value of grow() here is the previous number of WebAssembly pages.
Specifications
| Specification | Status | Comment |
|---|---|---|
| Web Assembly JavaScript API The definition of 'grow()' 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.