SyncMedia util- Convert a file to JSON Byte Array

<!DOCTYPE html>
<html>

  <head>
    <link rel="stylesheet" href="style.css">
    <script src="script.js"></script>
  </head>

  <body>
    <h1>Upload file</h1>
    <h2>See result in byte array</h2>
    <input type="file" onchange="readFile(this)" />
    <p>Result as byte[] JSON.Stringify</p>
    <textarea id="txtResult"></textarea>
  </body>

</html>

// Code goes here
var readFile = function (files) {
    var file = files.files[0];
    var reader = new FileReader();
    reader.onloadend = function () {
          console.log('finished reading file');
          encodeToByteArray(reader.result);
        }
    
    if (file) {
        //reader.readAsDataURL(file);
        reader.readAsArrayBuffer(file);
    } else {
       console.log('could not read file');
    }
};
        
var encodeToByteArray = function (arrayBuffer) {

    var byteArray = new Uint8Array(arrayBuffer);

    var arr = [];
    for (var i = 0; i < byteArray.byteLength; i++) {
        // do something with each byte in the array
        arr.push(byteArray[i]);
    }

    var arrString = JSON.stringify(arr);
    document.getElementById("txtResult").value = arrString;
   
};