Converting between strings and ArrayBuffers

Question

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

Answer 1

Unlike the solutions here, I needed to convert to/from UTF-8 data. For this purpose, I coded the following two functions, using the (un)escape/(en)decodeURIComponent trick. They're pretty wasteful of memory, allocating 9 times the length of the encoded utf8-string, though those should be recovered by gc. Just don't use them for 100mb text.

function utf8AbFromStr(str) {
    var strUtf8 = unescape(encodeURIComponent(str));
    var ab = new Uint8Array(strUtf8.length);
    for (var i = 0; i < strUtf8.length; i++) {
        ab[i] = strUtf8.charCodeAt(i);
    }
    return ab;
}

function strFromUtf8Ab(ab) {
    return decodeURIComponent(escape(String.fromCharCode.apply(null, ab)));
}

Checking that it works:

strFromUtf8Ab(utf8AbFromStr('latinкирилицаαβγδεζηあいうえお'))
-> "latinкирилицаαβγδεζηあいうえお"