Quick Bytes: Javascript Hex To Uint8Array

In a recent project I needed some javascript code to take a hex string and then convert to a Uint8Array.

Here's some quick code to get that done.

function hexStringToUint8Array(hexString) {
    if (hexString.length % 2 !== 0) {
        throw "Invalid hexString";
    }
    var arrayBuffer = new Uint8Array(hexString.length / 2);
    for (var i = 0; i < hexString.length; i += 2) {
        var byteValue = parseInt(hexString.substring(i, i + 2), 16);
        if (isNaN(byteValue)) {
            throw "Invalid hexString";
        }
        arrayBuffer[i / 2] = byteValue;
    }
    return arrayBuffer;
}