How to convert a JavaScript Typed Array into a JavaScript Array

Question

I have a JavaScript Float32Array, and I would like to convert it into a regular JavaScript Array. How can I do this?

Note that the accepted answer works for all of the Javascript Typed Arrays, eg Int8Array, Float64Array, etc. Question title could be changed to reflect this, so it's more helpful for people searching for this answer. — Daniel Howard, Feb 20 '14 at 17:54
I submitted a change proposal to the topic and question formulation. — marcusstenbeck, Sep 25 '14 at 10:57
One use case for this would be when you want to modify typed arrays with dat.GUI — xeolabs, Jan 02 '17 at 18:41

Cody Piersall · Answer 1 · 2020-05-06T15:22:48.923

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If you don't need to support old browsers (including IE, unfortunately), you can use Array.from, which was added to ES6:

var array = Array.from(floatarr);

This now works in the new releases of every browser (except IE), and it works on all major mobile browsers too.

edited May 06 '20 at 15:22

answered May 31 '16 at 16:13

Cody Piersall

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Agreed. One can also use the [spread syntax](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_syntax) in an array literal to achieve the same result. Like: `[...new Float32Array(16)]`. – Berkant İpek Sep 08 '20 at 10:06

score 45 · Answer 2 · edited Apr 17 '23 at 09:40

45

Use Array.prototype.slice to convert Float32Array to Array. jsfiddle

var floatarr = new Float32Array(12);
var array =  Array.prototype.slice.call(floatarr);

edited Apr 17 '23 at 09:40

Yves M.

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answered Oct 06 '12 at 14:29

Anoop

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Join seems to work too, nice trick ! Array.prototype.join.call( floatarr, ',') – Ray Hulha May 30 '13 at 00:17
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Wouldn't this easily exceed the stack size on large arrays? – John Weisz Feb 09 '18 at 11:34
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@JohnWeisz No, `floatarr` is passed as `this`. – Konrad Borowski Dec 12 '20 at 12:26

Denys Séguret · Answer 3 · 2012-10-06T14:37:13.760

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You can use it as any array, which means you can do this :

var arr = [];
for (var i=0; i<myFloat32array.length; i++) arr[i] = myFloat32array[i];

But it's usually more efficient to use it as a Float32Array instead of converting it.

If you don't want to mix different types of values, don't convert it.

edited Oct 06 '12 at 14:37

answered Oct 06 '12 at 14:26

Denys Séguret

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score 0 · Answer 4 · answered Dec 27 '22 at 14:32

In one shot:

Object.prototype.toArray=Array.prototype.slice;

Then you can use it this way:

fa32 = new Float32Array([1.0010000467300415, 1.0019999742507935, 2.003000020980835]);
fa64 = new Float64Array([1.0010000467300415, 1.0019999742507935, 2.003000020980835]);

Object.prototype.toArray = Array.prototype.slice

console.log("fa32", fa32.toArray());
console.log("fa64", fa64.toArray());

How to convert a JavaScript Typed Array into a JavaScript Array

4 Answers4

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