Javascript Convert String to Byte Array

StringToByteArray.js

var url = "Hello World";
var data = [];
for (var i = 0; i < url.length; i++){  
    data.push(url.charCodeAt(i));
}

function unpack(str) {
    var bytes = [];
    for(var i = 0; i < str.length; i++) {
        var char = str.charCodeAt(i);
        bytes.push(char >>> 8);
        bytes.push(char & 0xFF);
    }
    return bytes;
}

this is the correct way to extract the bytes a JavaScript string is made of

String.charCodeAt() returns a 16 bit unsigned integer, it must be split into two bytes if exceeds 0xff