How can I merge TypedArrays in JavaScript?

javascript typed-arrays
yomotsu picture yomotsu · Dec 28, 2012 · Viewed 28.4k times · Source

I'd like to merge multiple arraybuffers to create a Blob. however, as you know, TypedArray dosen't have "push" or useful methods...

E.g.:

var a = new Int8Array( [ 1, 2, 3 ] );
var b = new Int8Array( [ 4, 5, 6 ] );

As a result, I'd like to get [ 1, 2, 3, 4, 5, 6 ].

Answer

Prinzhorn picture Prinzhorn · Dec 28, 2012

Use the set method. But note, that you now need twice the memory!

var a = new Int8Array( [ 1, 2, 3 ] );
var b = new Int8Array( [ 4, 5, 6 ] );

var c = new Int8Array(a.length + b.length);
c.set(a);
c.set(b, a.length);

console.log(a);
console.log(b);
console.log(c);

Related questions

Converting between strings and ArrayBuffers

Is there a commonly accepted technique for efficiently converting JavaScript strings to ArrayBuffers and vice-versa? Specifically, I'd like to be able to write the contents of an ArrayBuffer to localStorage and to read it back.

Read More
What's the most straightforward way to copy an ArrayBuffer object?

I'm working with ArrayBuffer objects, and I would like to duplicate them. While this is rather easy with actual pointers and memcpy, I couldn't find any straightforward way to do it in Javascript. Right now, this is how I copy …

Read More
How to append bytes, multi-bytes and buffer to ArrayBuffer in javascript?

Javascript ArrayBuffer or TypedArrays dont have any kind of appendByte(), appendBytes(), or appendBuffer() methods. So if I want to fill an ArrayBuffer one value at a time, how do I do it? var firstVal = 0xAB; // 1 byte var secondVal = 0x3D7…

Read More