Conversion between UTF-8 ArrayBuffer and String

Question

I have an ArrayBuffer which contains a string encoded using UTF-8 and I can't find a standard way of converting such ArrayBuffer into a JS String (which I understand is encoded using UTF-16).

I've seen this code in numerous places, but I fail to see how it would work with any UTF-8 code points that are longer than 1 byte.

return String.fromCharCode.apply(null, new Uint8Array(data));

Similarly, I can't find a standard way of converting from a String to a UTF-8 encoded ArrayBuffer.

Answer 1

function stringToUint(string) {
    var string = btoa(unescape(encodeURIComponent(string))),
        charList = string.split(''),
        uintArray = [];
    for (var i = 0; i < charList.length; i++) {
        uintArray.push(charList[i].charCodeAt(0));
    }
    return new Uint8Array(uintArray);
}

function uintToString(uintArray) {
    var encodedString = String.fromCharCode.apply(null, uintArray),
        decodedString = decodeURIComponent(escape(atob(encodedString)));
    return decodedString;
}

I have done, with some help from the internet, these little functions, they should solve your problems! Here is the working JSFiddle.

EDIT:

Since the source of the Uint8Array is external and you can't use atob you just need to remove it(working fiddle):

function uintToString(uintArray) {
    var encodedString = String.fromCharCode.apply(null, uintArray),
        decodedString = decodeURIComponent(escape(encodedString));
    return decodedString;
}

Warning: escape and unescape is removed from web standards. See this.